fix(core): use schemaGenerator option disableForeignKeys when dropping database

[luksiv]

closes #3004

[luksiv]

@B4nan could you re-trigger tests, because yesterday Github Actions were down.

[B4nan]

Well, the tests ran, and timed out after 6 hours because of one broken assertion that caused the tests to hang (as no orm.close() was called as the test failed). This is something to be fixed, rerunning the tests won't help. There are test failures in tests/features/schema-generator/SchemaGenerator.mysql2.test.ts because of this change, and maybe elsewhere too.

The problem is in circular FK between author2 and book2 tables (and probably other similar issues in other relations), I believe we actually need to disable the FK checks for this use case in mysql (dropping tables). The alternative would be to first drop the FKs, which actually sounds quite reasonable, but should be rather a separate PR.

[luksiv]

If you can try to resolve this, I would really appreciate it, since this is a little bit too advanced for me to try to do without pouring a lot of hours into trying to fix this 😄

[B4nan]

Yeah sure, it should be rather easy, I can look into that myself when I find some spare time.

[B4nan]

I ended up taking a bit different approach as the default was not needed in dropSchema, should be resolved via b1b5f55