Add benchmarks to pipeline (#1074)

* [Do not merge] add benchmarks to pipeline

* disable jobs for test

* Revert "[Do not merge] add benchmarks to pipeline"

This reverts commit af3cca09f2bbec7ab75e1e905314356ce4405a6f.

* add weights tag

* add stage

* empty before_script for benches

* run benchmarks on ci6

* disable cargo target dir

* disable pre-cache

* add CARGO_TARGET_DIR var to bench script

* debug

* debug

* fix script path

* divide build and benchmark into 2 jobs

* fix bench build

* small fix

* reduce benchmark output log

* add push github

* add push gh

* add after_script

* typo fix

* typo fix

* fix curl

* fix git config

* add title and body to pr

* final check that everything works

* final check that everything works

* return jobs back

* fix rules

* cancel changes benchmarks.sh

* Apply suggestions from code review

Co-authored-by: Denis Pisarev <[email protected]>

* rename job

* change benches jobs to run on release-parachains-v*

* remove master refs

Co-authored-by: Denis Pisarev <[email protected]>