Upgrade TypeORM to v3

[wowczarczyk]

TypeORM has been released with version 3 in March:

https://github.com/typeorm/typeorm/blob/master/CHANGELOG.md

There is a PR in Nest.js to make it support the new version:

nestjs/typeorm#1233

I saw that Renovate tried to bump the version itself but failed:

#1487

I think that there will be not so many changes to make (Judging by failed test, but might be wrong here)

[Diluka]

@nestjs/typeorm now is support v0.3 above only https://github.com/nestjs/typeorm/releases/tag/8.1.0

[nikun]

any plan for upgrade to typeorm V3 ?

[abidon]

In our case, this patch (#1549) was enough.

There's obviously more to do to remove usage of deprecated features, but in our case, it allowed us to bump NestJS and TypeORM versions.

[TriPSs]

TypeORM v3 support is now released in the alpha version of my fork together with all the fixes from here