enforce int primitive type for enum

[omissis]

• Adds enforcing integer type for enum values
• Fixes linter complains

[codecov[bot]]

Codecov Report

Attention: 17 lines in your changes are missing coverage. Please review.

Comparison is base (5362d2e) 77.85% compared to head (1eccf52) 61.84%. Report is 3 commits behind head on main.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #126 +/- ## =========================================== - Coverage 77.85% 61.84% -16.01% =========================================== Files 12 23 +11 Lines 1567 2034 +467 =========================================== + Hits 1220 1258 +38 - Misses 270 692 +422 - Partials 77 84 +7 ``` | [Files](https://app.codecov.io/gh/omissis/go-jsonschema/pull/126?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Claudio+Beatrice) | Coverage Δ | | |---|---|---| | [tests/data/validation/6.1.2\_enum.go](https://app.codecov.io/gh/omissis/go-jsonschema/pull/126?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Claudio+Beatrice#diff-dGVzdHMvZGF0YS92YWxpZGF0aW9uLzYuMS4yX2VudW0uZ28=) | `0.00% <ø> (ø)` | | | [tests/data/validation/6.3.1\_maxLength.go](https://app.codecov.io/gh/omissis/go-jsonschema/pull/126?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Claudio+Beatrice#diff-dGVzdHMvZGF0YS92YWxpZGF0aW9uLzYuMy4xX21heExlbmd0aC5nbw==) | `71.42% <ø> (ø)` | | | [tests/data/validation/6.3.2\_minLength.go](https://app.codecov.io/gh/omissis/go-jsonschema/pull/126?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Claudio+Beatrice#diff-dGVzdHMvZGF0YS92YWxpZGF0aW9uLzYuMy4yX21pbkxlbmd0aC5nbw==) | `71.42% <ø> (ø)` | | | [pkg/generator/generate.go](https://app.codecov.io/gh/omissis/go-jsonschema/pull/126?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Claudio+Beatrice#diff-cGtnL2dlbmVyYXRvci9nZW5lcmF0ZS5nbw==) | `75.77% <71.42%> (-0.04%)` | :arrow_down: | | [tests/utils.go](https://app.codecov.io/gh/omissis/go-jsonschema/pull/126?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Claudio+Beatrice#diff-dGVzdHMvdXRpbHMuZ28=) | `16.66% <16.66%> (ø)` | | ... and [7 files with indirect coverage changes](https://app.codecov.io/gh/omissis/go-jsonschema/pull/126/indirect-changes?src=pr&el=tree-more&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=Claudio+Beatrice)

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[omissis]

This PR replaces #103 (simply rebases it and fixes an issue coming from main`