SnapshotManager: use QueryBuilder

[Hanmac]

Subject

I am targeting this branch, because it should be BC.

Still Draft, i need to update the other queries, and i need to write a functional testcase using KernelTestCase and a Test Database

Closes #{put_issue_number_here}.

Changelog

### Changed
- Updated SnapshotManger to use QueryBuilder instead of native SQL

[Hanmac]

first query is done, one more to go

[Hanmac]

it seems it doesn't crash on newer doctrine orm, i need to debug that more

[VincentLanglet]

it seems it doesn't crash on newer doctrine orm, i need to debug that more

You're allowed to bump the doctrine orm version if needed

Let's clarify what we do about getSingleColumnResult

[eerison]

for me it's fine :) , good job @Hanmac 👏🏼

[eerison]

@Hanmac can you just update your PR's description please! specially the Changelog