BUG-2022: String Type pattern parsing and resolving fix.

Added fix during string type pattern restriction resolution in ParserListenerUtils. Now if pattern statement in yang model contains uncompilable string
the warning is logged and pattern restriction is not among types restrictions.
Each pattern is wrapped between "^"and "$" symbols.

Modified exisiting tests and test resources for testing of transofrmation of incorrect pattern regular expressions.

Change-Id: I86d6066b93e2f21b5c826729469228286a31965d
Signed-off-by: Lukas Sedlak <lsedlak@cisco.com>
Merge "BUG-2022: String Type pattern parsing and resolving fix." into stable/helium