Fixes quantum.api.v2.base._filters to be more intuitive

Converts values in one place and sets dictonary according to the return value

Fixes bug #1092977

Change-Id: I05dd9b24a8ab20f8c302c22f5bdda2a80ec90e19
Remove unused imports in unit tests

Change-Id: I10401bc240b2a7aebe6317067dafe8bfe35264f8
Merge "Fixes quantum.api.v2.base._filters to be more intuitive"
Merge "Remove unused imports in unit tests"