refactor: unifies spread types in their proper places

[wellwelwel]

It's a large TypeScript refactoring that includes every single *.ts file in the entire project.

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Why?

Many types are confusing because they are redefined several times, for example:

• Pool types are spread and defined in index.d.ts, typings/mysql/index.d.ts and typings/mysql/lib/Pool.d.ts at the same time
  • The same for Connection, ConnectionOptions, execute, query, etc.
• execute and query are complex and have to do several ctrl + c and v around the types
• Sometimes a type is only present in one of them, in other as overwritten and another time it's just repeated

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To consider

• It makes new TS contributions much easier:
  • Do you want to change some type in Connection? It's simple: go to Connection.d.ts file 👨🏻‍💻
• It makes creating new TS tests more practical
• By certain way, many past changes that have caused TS errors is because the types have been spread around

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CI

• npm run lint:code now checks for every *.ts file (including the tests)

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What does this refactoring change?

In final usage, nothing. It's just a refactoring, but... 🤹🏻‍♀️

• ✅ These changes resolves 100% of eslint errors in *.ts

• ✅ Unifies the types in their proper places:

  • Pool as example: now, all typings are defined in typings/mysql/lib/Pool.d.ts
  • execute and query overloads too. Now both can be reused:
    • If you change something in type execute or query, it will automatically affect all types that need it (Connection, PoolConnection, etc.) 🤹🏻‍♀️

• ✅ Increments NodeNext TypeScript compatibility by requires the .js in local imports for *.ts files

• ✅ Resolves circular imports in every *.ts file

• ✅ Patterns all imports as import any from './'

  • Before, it was mixed with import any = require('./')

• ℹ️ Removes older TypeScript tests that are unused

  • Then, removes @types/mocha, @types/chai, mocha and chai dependencies

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Lastly

It's the new index.d.ts:

export * from './typings/mysql/index.js';

Yes, it's everything, because each type is in its proper place and the index.d.ts just calls them 🥷🏻✨

[sidorares]

great work @wellwelwel
I just glanced over the changes I think it looks good but would be really good if someone else could take another look

[wellwelwel]

@sidorares, I'm thinking of closing this PR.
A large change like that it's hard to get a good review.

Instead, I'm considering bringing here a Milestone that I have into a private repository where I test everything before bringing it here.

Then, reach exactly at the same place as this PR, but in stages.

Independently of closing or not, I think it's good to bring it here.
By this way, my PRs would be more easily planned and everyone would be aware of everything

[wellwelwel]

See #2072