features: Implement JSON trace format

[p-offtermatt]

HOW-TO-READ commit by commit:

81ec379 adds first version of the parser and writer with test files
8c42810 is a large commit which exports action and state wherever they are mentioned. just a chore. all changes should be the words action to Action and state to State
ec6a6bf is also a large commit. It exports all fields of all action types. All changes should be capitalizing words
f1c3c0f is also a chore: it maps strings of action types to their action structs
e6753ff refactors the first version of the parser and writer, and contains much of the final logic
85f5d15 adds some examples of what the trace format looks like

Description

Add a writer and reader for a simple JSON file format which is marshalled directly from
the Step objects in our code.

There are some chores which involve changing lots of fields to be exported (so that they can be properly Unmarshalled/Marshalled).

Closes: #875

Add a parser/writer to input traces from files for the e2e tests.

Most critical files:

• tests/e2e/trace_*.go - the new files in this PR

• The rest are almost only chore changes to export some fields which otherwise gave me trouble with cmp and Json Marshal/Unmarshaling

• See an example of the trace format here: tests/e2e/traces/start_provider_chain.json

• Files in tests/e2e/traces are meant to eventually be input files for e2e tests

• Files in tests/e2e/tracehandler_testdata are meant to be tests for the parser

Author Checklist

All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.

I have...

• Included the correct type prefix in the PR title
• Targeted the correct branch (see PR Targeting)
• Provided a link to the relevant issue or specification
• Included the necessary unit and integration tests
• Included comments for documenting Go code
• Reviewed "Files changed" and left comments if necessary
• Confirmed all CI checks have passed

Reviewers Checklist

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your handle next to the items reviewed if you only reviewed selected items.

I have...

• confirmed the correct type prefix in the PR title
• confirmed ! in the type prefix if API or client breaking change
• confirmed all author checklist items have been addressed
• reviewed state machine logic
• reviewed API design and naming
• reviewed documentation is accurate
• reviewed tests and test coverage

[MSalopek]

Thank you for the changes and thank you for cleaning up history and making a concise description of the changes per commit.

Since none of the work outlined here impacts the the actual testing procedure let's proceed with the actual changes. Generally, we should strive for small PRs but in this case most of the complexity comes from having to export all the previously unexported fields to enable JSON unmarshalling.

Approve!