MapperTestCase: Mock SqlFactory::getSqlObject more completely

## Whenever `$table` is given to `getSqlObject`, the returned mocked SQL object responds appropriately.

### Acceptance Criteria
1. MapperTestCase is backwards compatible. (Shouldn't actually require any BC provisions.)
1. Whenever a tested mapper calls `$this->sqlFactory->getSqlObject($this->dbAdapter, $otherTable)`, the mocked Sql object that is returned responds to the given `$otherTable`. That is to say, queries that are captured prefix column names with the correct table name.
 - To put it in simpler terms: "The captured queries actually match the queries Zend Db would perform on the database". (Perhaps this should be filed as a bug?)

### Tasks
- Modify `MapperTestCase::getMockSql` and `MapperTestCase::setUpMockSqlFactory` to be aware of alternate table names.
- Remove duplicate code in `getMockSql`.

### Additional Notes
- None