Ability to set datanames in module's constructor

[donyunardi]

Summary

Related to insightsengineering/teal#143.

We need to review all modules to ensure there is a way for users to set datanames in the module. Upon review, we identified two modules that require updates:

• tm_g_barchart_simple
• tm_g_ci

Additionally, we discussed how tm_g_ci should be designed to use x_var, y_var, and color (which are data_extract_spec objects) when defining datanames, similar to the approach described here .

Acceptance Criteria

• Update the design of tm_g_barchart_simple and tm_g_ci to allow datanames to be set in the module's constructor.
• Design tm_g_ci to utilize x_var, y_var, and color as data_extract_spec objects when defining datanames.
• Ensure that every module provides a way to configure datanames (via argument, data extract spec, or other means) in the module's constructor.
• • Review and update roxygen note, if necessary.