Refactor LSP to use Symfony with test coverage

[osbre]

In order to make LSP the best it can be, we have to first make the code "maintainable". This PR refactors LSP and adds test coverage to ensure things keep working in the future. Passwords are now properly hashed using Bcrypt. Whenever someone logs-in, we re-hash the password thanks to Symfony's config.

Live environment if you would like to test it yourself: https://lmmsio-production-lj6ate.laravel.cloud/lsp (note this hosting uses ephemeral storage so files won't last long - not a code bug)

If you have a dedicated .env for production, set LSP_DATA_DIR="%kernel.project_dir%/tmp" there.

I decided to split the previously "all-in-one" route into separate paths, ie /lsp/{id}, but there's now LegacyRedirectResolver for compatibility redirects.

There's now GitHub Actions config to run tests on every change/other PRs. Feel free to ask any follow-up questions.

Don't forget to run composer i locally.

[osbre]

Dependency lockfile has greatly contributed to the length of this PR changes stats, so don't be too scared 👀 😅

[osbre]

One more note about passwords: the re-hashed password gets stored in the pw column, because current password column is too small for bcrypt, and since the pw column was previously unused - sounds like finally an opportunity to put it into use without having to modify the existing db schema.

[tresf]

One more note about passwords: the re-hashed password gets stored in the pw column, because current password column is too small for bcrypt, and since the pw column was previously unused - sounds like finally an opportunity to put it into use without having to modify the existing db schema.

My advice is to update the schema and check the hash length before comparing so we can support both old and new. I think pw once stored the temporary unencrypted version. If it's not needed, it should be removed.

[osbre]

Thanks. Now there's 05-change-password-size.sql and 06-drop-legacy-pw-column.sql migrations attached.

I couldn't find any usage of the pw column in previous codebase, so it's safe to drop.