Refactor Generator

[jribbink]

Closes #1774

Description

Most of the work is just reoganizing logic

• Removed branching logic based on template type in Generator.generate function. This logic was all moved to the TemplateType structs. This helps us generalize a bit better without needing special handling for each new type (i.e. README.md, tests, and anything else in the future.
• Added a "TestTemplate" for generating tests instead of embedding this logic inside of Contract templates

I feel like this could be potentially abstracted further by breaking the template files themselves out of the generator, but probably out of scope for this PR/unnecessary right now and I think what's been changed in this PR is already an improvement.

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For contributor use:

• Targeted PR against master branch
• Linked to Github issue with discussion and accepted design OR link to spec that describes this work
• Code follows the standards mentioned here
• Updated relevant documentation
• Re-reviewed Files changed in the Github PR explorer
• Added appropriate labels

[codecov-commenter]

Codecov Report

Attention: Patch coverage is 67.10526% with 50 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
internal/super/generator/generator.go	71.42%	8 Missing and 8 partials ⚠️
internal/super/setup.go	0.00%	14 Missing ⚠️
internal/super/generate.go	0.00%	9 Missing ⚠️
internal/super/generator/contract_template.go	82.92%	5 Missing and 2 partials ⚠️
internal/super/generator/test_template.go	83.33%	2 Missing ⚠️
internal/super/generator/script_template.go	90.00%	1 Missing ⚠️
internal/super/generator/transaction_template.go	90.00%	1 Missing ⚠️

📢 Thoughts on this report? Let us know!

[chasefleming]

@jribbink You tested this manually with init, generate, and with the custom directory flag in generate?

[jribbink]

@jribbink You tested this manually with init, generate, and with the custom directory flag in generate?

Yup. No regressions. It fixes some issues in scripts/tx/test templates with missing values as well.