Skip application of 'id' in TH code

This is just beautification when dumping splices to stdout, as ghc
will optimise the 'id' away anyway.

Original generate code:

  opToArgs QueryTags kind name = J.showJSON (id kind, id name)

Afterwards:

  opToArgs QueryTags kind name = J.showJSON (kind, name)

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>