Fix bug when creating SRG termination points

Fix bug when creating SRG termination points

When a ROADM node includes multiple SRGs such as SRG1, SRG10, SRG11,
etc., the termination points (tp-id) created under SRG1 in the
openroadm topology included erroneous entries such as SRG10-PPn-TXRX
under SRG1. This was caused by the createTopologyShard method filtering
and selecting all logical connection points in the port mapping list
containing SRG1 as a substring which is also true for SRG10, SRG11,
etc. With this patch, the whole string before the first "-" is used for
comparison instead.
Also, add a specific UT to check this use case.

JIRA: TRNSPRTPCE-664
Signed-off-by: Jonas Mårtensson <jonas.martensson@ri.se>
Change-Id: Iab2802e1bac4e48aafeb4518d876c32b990742c3