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.

---

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.

Project coverage is 29.73%. Comparing base (3b885aa) to head (0a5cb25).

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 ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #1772      +/-   ##
==========================================
+ Coverage   29.65%   29.73%   +0.08%     
==========================================
  Files          89       94       +5     
  Lines        5197     5176      -21     
==========================================
- Hits         1541     1539       -2     
+ Misses       3469     3458      -11     
+ Partials      187      179       -8     

Flag	Coverage Δ
unittests	29.73% <67.10%> (+0.08%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

[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.