The nvim-treesitter highlights files that we're using for most of our

supported languages make use of several custom predicates and

directives.
This change implements the following:

any-contains?
contains?
gsub!
has-ancestor?
has-parent?
not-has-ancestor?
not-has-parent?

Directives used in queries files which are not (yet) implemented here:

offset!

Predicates and directives implemented in neovim but which are not used

in any of the query files we are using:

any-lua-match?
any-vim-match?
not-vim-match?
vim-match?
trim!

Ran unit tests.
Verified that syntax highlighting that used these predicates and

  directives worked as expected.