src/test/mon: test_monmap_monitor.cc

src/test/mon: test_monmap_monitor.cc

Added the following test cases:
- Test success when explicitly supplied tiebreaker
- Test success when auto-selecting tiebreaker monitor
- Test success with minimal valid configuration (1 monitor per zone)
- Test success with auto-selection and minimal config (1 monitor per zone)
- Test success when strategy is automatically changed to CONNECTIVITY
- Test failure when auto-selecting and tiebreaker is in a data zone
- Test failure when explicitly specifying tiebreaker in a data zone
- Test failure when multiple potential tiebreakers exist
- Test failure when one data zone has 0 monitors
- Test failure when tiebreaker monitor doesn't exist

Signed-off-by: Kamoltat (Junior) Sirivadhna <ksirivad@redhat.com>