Fix "ends-with" query syntax to conform with xPath definition

"ends-with" is HOW we resolve it in sql query. 'descendant anywhere' is the correct Path name for the '//' operator
- Updated method names, variable names, test description to reflect the correct terminolgy
- Udpated query to always perfix the target (descendant name) with an '\' so it alwasy only matches whole node names
- Updated regex for cpsPath to NOT accept triple /// (as per xPath this is invalid since a ndoeName cannot start with or contain a node separator

Issue-ID: CPS-336

Signed-off-by: ToineSiebelink <toine.siebelink@est.tech>
Change-Id: I9f181d6986d038311b839e3f9c5afc4237c7d347