Allow passing query Expression as column in Many-to-Many relationship

[plumthedev]

Query builder supports query expressions when Many-to-Many relationships.
I have fixed that by check if passed column to be qualified with explicit table name is query expression, if so I made a return to use it as developer requested, without qualifying. Added support for expression in clauses methods types. Covered by test which is verifying if base relation methods receives expression.
Moreover, PHPUnit test case replaced with Mockery adapter test case, which closes Mockery by themself.

This MR solves #50787

[tpetry]

Please use the expression functions from the query grammar. These should be isExpression() and getValue().

And please create tests so this issue can‘t be re-introduced anymore.

[plumthedev]

Dear @tpetry
Thanks for advice, added. Please check it now.

[tpetry]

Looks better 👍

[GrahamCampbell]

I'm not so sure this change belongs in the framework core. The use case seems pretty edge case.

[GrahamCampbell]

This is also a breaking change for existing packages that extend the framework's relationship classes.

[plumthedev]

I believe that is not a BC as I have fixed edge case which was not working properly. Even if third parties used expressions they are not working correctly

[tpetry]

For 10.x we fixed several cases were expressions had not been handled correctly. To be more clear, 10.x added the bc break because my expression could only handle correctly everything i new off. But expressions could have been used at a ton of places - normally not documented. So in my opinion, this is fixing a bug like many times before.

[ccharz]

This change seems to cause an issue when using an belongsToMany relation in combination with "withoutGlobalScopes". In my case the global scopes are not removed. If i revert this change, all works as expected.

Would it be possible to change the call from $this->getGrammar()->isExpression($column) to $this->query->getQuery()->getGrammar()->isExpression($column) so the getGrammar() call doesn't get forwarded to the builders toBase() method (which applies all the scopes)?

[tpetry]

@ccharz Please create a new issue with a reproducible example. This bug get easily missed as a simple comment.

[ccharz]

@tpetry Okay - I have created the issue #50945