fix: handle missing or broken locales main index files

[ST-DDT]

While preparing #477 I encountered the issue, that I renamed the files, but did not fix the imports (as that is supposed to be done by the generate:locales script instead.

However, the script failed to execute, because it tries to import the locale to read it's title and separator.

$ pnpm run generate:locales

> @faker-js/faker@6.0.0-alpha.6 generate:locales ~/git/Faker/faker
> esno ./scripts/generateLocales.ts

Error: Cannot find module './bicycle'
Require stack:
- ~/git/Faker/faker/src/locales/en/vehicle/index.ts
- ~/git/Faker/faker/src/locales/en/index.ts
- ~/git/Faker/faker/scripts/generateLocales.ts
    at Function.Module._resolveFilename (node:internal/modules/cjs/loader:933:15)
    at Function.Module._load (node:internal/modules/cjs/loader:778:27)
    at Module.require (node:internal/modules/cjs/loader:1005:19)
    at require (node:internal/modules/cjs/helpers:102:18)
    at Object.<anonymous> (~/git/Faker/faker/src/locales/en/vehicle/index.ts:6:21)
    at Module._compile (node:internal/modules/cjs/loader:1101:14)
    at Module._compile (~/git/Faker/faker/node_modules/.pnpm/esbuild-register@3.3.2_esbuild@0.14.21/node_modules/esbuild-register/dist/node.js:2258:26)
    at Module._extensions..js (node:internal/modules/cjs/loader:1153:10)
    at Object.newLoader [as .ts] (~/git/Faker/faker/node_modules/.pnpm/esbuild-register@3.3.2_esbuild@0.14.21/node_modules/esbuild-register/dist/node.js:2262:9)
    at Module.load (node:internal/modules/cjs/loader:981:32) {
  code: 'MODULE_NOT_FOUND',
  requireStack: [
    '~/git/Faker/faker/src/locales/en/vehicle/index.ts',
    '~/git/Faker/faker/src/locales/en/index.ts',
    '~/git/Faker/faker/scripts/generateLocales.ts'
  ]
}

This PR prevents these kind of issues, by adding two fallback layers.

1. If the module fails to load, it will attempt to manually parse the file.
2. If that also fails, it will just generate a default value, in an attempt to create at least a working and improvable file.

With this new version it is possible to remove or invalidate all index.ts files from src/locales and regenerate them (without the original title though).

[codecov]

Codecov Report

Merging #478 (92b7b1f) into main (829f7ff) will decrease coverage by 0.00%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##             main     #478      +/-   ##
==========================================
- Coverage   99.34%   99.34%   -0.01%     
==========================================
  Files        1919     1919              
  Lines      176291   176291              
  Branches      898      898              
==========================================
- Hits       175132   175131       -1     
- Misses       1103     1104       +1     
  Partials       56       56              

Impacted Files	Coverage Δ
src/helpers.ts	99.39% <0.00%> (-0.16%)	⬇️