Merge branch 'jk/complete-git-switch'

Merge branch 'jk/complete-git-switch'

The command line completion (in contrib/) learned to complete
options that the "git switch" command takes.

* jk/complete-git-switch:
  completion: improve handling of --orphan option of switch/checkout
  completion: improve handling of -c/-C and -b/-B in switch/checkout
  completion: improve handling of --track in switch/checkout
  completion: improve handling of --detach in checkout
  completion: improve completion for git switch with no options
  completion: improve handling of DWIM mode for switch/checkout
  completion: perform DWIM logic directly in __git_complete_refs
  completion: extract function __git_dwim_remote_heads
  completion: replace overloaded track term for __git_complete_refs
  completion: add tests showing subpar switch/checkout --orphan logic
  completion: add tests showing subpar -c/C argument completion
  completion: add tests showing subpar -c/-C startpoint completion
  completion: add tests showing subpar switch/checkout --track logic
  completion: add tests showing subar checkout --detach logic
  completion: add tests showing subpar DWIM logic for switch/checkout
  completion: add test showing subpar git switch completion