Merge branch 'cc/promisor-remote-capability'

The "promisor-remote" capability mechanism has been updated to
allow the "partialCloneFilter" settings and the "token" value to be
communicated from the server side.

* cc/promisor-remote-capability:
  promisor-remote: use string_list_split() in mark_remotes_as_accepted()
  promisor-remote: allow a client to check fields
  promisor-remote: use string_list_split() in filter_promisor_remote()
  promisor-remote: refactor how we parse advertised fields
  promisor-remote: use string constants for 'name' and 'url' too
  promisor-remote: allow a server to advertise more fields
  promisor-remote: refactor to get rid of 'struct strvec'