Implement knit_print and render methods for reporting

[Puzzled-Face]

See #768 for design details.

This is the issue to manage implementation of S3 knit_print and S4 render methods for crmPack. Please use the bullet list below to manage the implementation of each sub task in the list. Edit this issue to indicate that you have taken responsibility for each sub-task.

To avoid merge conflicts, I suggest adding new features in files named helpers_knitr_<subtask>.R. Once all sub tasks have been completed, the final step can be to combine all the task-specific files into helpers-knitr.R.

The knit_print methods for each sub-class of GeneralModel will be the longest and most fiddly to write. For this reason I have separated them out into individual sub-tasks. It might be possible to combine the implementation of one or two methods into a single PR.

To do

• Implement knit_print for subclasses of Data (including tests) [Puzzled-Face Implement knit_print for subclasses of Data #791]
• Implement knit_print for subclasses of CohortSize (including tests) [Puzzled-Face Implement knit_print for subclasses of CohortSize (including tests) #775]
• Implement knit_print for subclasses of Increments (including tests) [Puzzled-Face Implement knit_print for subclasses of Increments #785]
• Implement knit_print for subclasses of NextBest (including tests) [Puzzled-Face Implement knit_print for subclasses of NextBest #807]
• Implement knit_print for subclasses of Stopping (including tests) [Puzzled-Face Implement knit_print for subclasses of Stopping #803]
• Implement knit_print for subclasses of Design (including tests) [Puzzled-Face Implement knit_print for subclasses of Design #814]
• Implement knit_print for subclasses of Simulations (including tests)
• Implement knit_print for subclasses of SimulationSummary (including tests)
• Implement knit_print for ModelLogNormal (including tests)
• Implement knit_print for LogisticLogNormalSub (including tests) [@Puzzled-Face Implement knit_print for GeneralModel objects #795]
• Implement knit_print for LogisticKadane (including tests) [@Puzzled-Face Implement knit_print for subclasses of Design #814]
• Implement knit_print for LogisticNormalMixture (including tests) [@Puzzled-Face Implement knit_print for GeneralModel objects #795]
• Implement knit_print for LogisticNormalFixedMixture (including tests) [@Puzzled-Face Implement knit_print for GeneralModel objects #795]
• Implement knit_print for DualEndpoint (including tests) [@Puzzled-Face Implement knit_print for subclasses of Design #814]
• Implement knit_print for OneParLogNormalPrior (including tests) [@Puzzled-Face Implement knit_print for subclasses of Design #814]
• Implement knit_print for OneParExpPrior (including tests) [@Puzzled-Face Implement knit_print for subclasses of Design #814]
• Implement knit_print for LogisticNormal (including tests) [@Puzzled-Face Implement knit_print for GeneralModel objects #795]
• Implement knit_print for LogisticLogNormal (including tests) [@Puzzled-Face Implement knit_print for GeneralModel objects #795]
• Implement knit_print for ProbitLogNormal (including tests) [@Puzzled-Face Implement knit_print for GeneralModel objects #795]
• Implement knit_print for ProbitLogNormalRel (including tests)
• Implement knit_print for LogisticLogNormalGrouped (including tests) [@Puzzled-Face Implement knit_print for subclasses of Design #814]
• Implement knit_print for LogisticKadaneBetaGamma (including tests) [@Puzzled-Face Implement knit_print for subclasses of Design #814]
• Implement knit_print for DualEndpointRW (including tests) [@Puzzled-Face Implement knit_print for subclasses of Design #814]
• Implement knit_print for DualEndpointBeta (including tests) [@Puzzled-Face Implement knit_print for subclasses of Design #814]
• Implement knit_print for DualEndpointEmax (including tests) [@Puzzled-Face Implement knit_print for subclasses of Design #814]
• Implement knit_print for LogisticLogNormalMixture (including tests) [@Puzzled-Face Implement knit_print for subclasses of Design #814]
• Implement knit_print for DALogisticLogNormal (including tests) [@Puzzled-Face Implement knit_print for subclasses of Design #814]
• Implement knit_print for TITELogisticLogNormal (including tests)
• Implement knit_print for FractionalCRM (including tests)
• Implement knit_print for LogisticLogNormalOrdinal (including tests)
• Implement render (including tests)
• Ensure "check method exists" test fails when a knit_print method is not found rather than simply printing a warning
• Convert design document to vignette [@Puzzled-Face Write a knit_print vignette #829]
• Add @method roxygen statements to helpers_knitr_Increments.R, helpers_knitr_CohortSize.R and helpers_knitr_GeneralData.R, as per helpers_knitr_GeneralModel.R. [@Puzzled-Face Add @method roxygen statements to "early" knit_print methods #826]

[Puzzled-Face]

It appears that the S3 knit_print methods for each class are not registered until they are documented with devtools::document. Until then, they must be registered manually. For example

registerS3method("knit_print", "IncrementsRelativeDLTCurrent", knit_print.IncrementsRelativeDLTCurrent)

... and the correct way to document them is with

@method <method name> <class name>

for example

@method knit_print CohortSizeConst