[Clojure] refactor

[jrappen]

Additions:

• add merge-conflict-markers to string and regexp string bodies,
  compare [Common] Add git conflict marker highlighting #4047
• add regexp.clojure syntax with merge-conflict-markers in prototype
• add shebang tests (pos and neg)
• add syntax section markers

Changes:

• bump syntax v2
  • replace pop: true with pop: 1
  • fix meta_scope vs. meta_content_scope for regexp strings
• differentiate between #! line comments and shebang
  • link references for #! line comments
  • use var to sync shebang lang, compare [Common] Use variables to keep shebang in sync #4219
• move merge-conflict-markers tests

References:

• address [Common] Add git conflict marker highlighting #4047
• address [Common] Use variables to keep shebang in sync #4219