devel/googlemock, devel/googletest: Upgrade version 1.5 => 1.7

As part of the upgrade process:

• copy shebangfix and regression-test from googletest to googlemock
• convert regression-test to TEST option for better integration with poudriere and visibility for users
• make sure configure detects python2 to follow shebangfix
• add LICENSE=BSD3CLAUSE (idea from comment 0)
• strip libs per stage-qa
• enable pthreads by default in devel/googletest
• enable death tests in devel/googletest
• enable socket streaming in devel/googletest
• implement GetThreadCount for death tests in devel/googletest
• disable streaming tests that fail with old gcc on 9.x in googletest
• depend on googletest in googlemock as -lgmock fails otherwise [1]
• pass maintainership to the persistent submitter [2]

PR: 187562
PR: 192736 [2]
PR: 192042 [1]
Approved by: maintainer timeout (~8 months)
Submitted by: rakuco [1]
Submitted by: Jan Beich <jbeich@vfemail.net> [2]