Development and testing of new lines.

Make use of the workflow found at https://lhcb-dpa.web.cern.ch/lhcb-dpa/wp5/LineWritingInstructions.html#commit-a-stripping-line , such that Analyser -> WG_devbranch -> production branch

Each MR from analysers should contain:

• Names of new or updated lines
• Retention rates (see !1580 (merged) )
• Assigned to the relevant WG liaisons and linked to appropriate milestone
• Pointing to the relevant WG development branch