Move BuildMock to MockQueryable.EntityFrameworkCore

[skarllot]

Move the extension method BuildMock to the package MockQueryable.EntityFrameworkCore.

[ramantsitou]

Hello @skarllot could you provide more detailed reason why this change should be done?

[skarllot]

Because it does not depend on NSubstitute but only on the TestAsyncEnumerableEfCore class defined in MockQueryable.EntityFrameworkCore, it would allow sharing the implementation regardless of the mocking library used, and furthermore, allow using no mocking library at all if the user desires.

[ramantsitou]

Done in v7.0.2

[scp-mb]

Breaking change on a patch version? Not cool. Why not release is at 8.0.0 if it's got a breaking change in it.