TYPO3 Core

The column "fe_group" is defined as varchar everywhere in the core except in table "sys_collection".
This will cause some problems with some DBMS (e.g. PostgreSQL) as the FrontendGroupRestriction::class will generate a query which will e.g. check against empty string.
Thus the column "fe_group" should be unified to varchar.

Example:
The following tests fail with the column "fe_group" defined as integer:
- RecordCollectionRepositoryTest::doesFindByUidReturnAnObjectInFrontendMode
- RecordCollectionRepositoryTest::doesFindByUidRespectEnableFieldsInFrontendMode