Add update docs script to CI (#9219)

* Add update docs script to CI

Added a script to CI that will use the jsonrpc tool to update rpc
documentation then commit and push those to the wiki repo.

* fix gitlab ci lint

* Only apply jsonrpc docs update on tags

* Update gitlab-rpc-docs.sh

* Copy correct parity repo to jsonrpc folder

Copy correct parity repo to jsonrpc folder before attempting to build docs since the CI runner clones the repo as parity and not parity-ethereum.

* Fix JSONRPC docs CI job

Update remote config in wiki repo before pushing changes using a github
token for authentication. Add message to wiki tag when pushing changes.
Use project directory to correctly copy parity code base into the
jsonrpc repo for doc generation.

* Fix set_remote_wiki function call in CI