fix(manager/regex): depName requirement if using the recursive strategy (#16225)

* fix(manager/regex): depName requirement if using the recursive strategy

* chore(manager/regex): implement code suggestions

* chore: replace Boolean with Is function

* chore: abort if match strings are empty

* refactor: do not parse regexes on each recursion and filter after all matches are processed

* fixup! test name

* Revert "chore: abort if match strings are empty"

This reverts commit bf41a92f

* refactor: extract inline function

* fix: out-of-bound check

* feat: allow currentDigest as valid alternative to currentValue

* Update lib/modules/manager/regex/utils.ts

Co-authored-by: Michael Kriese <michael.kriese@visualon.de>

* chore: prettier

Co-authored-by: Michael Kriese <michael.kriese@visualon.de>