Roadmap - Introduce progress tracking setting

What does this MR do and why?

Introduces Progress tracking setting in sidebar. Allows user to switch epic progress tracking between weight and issue counts.

This setting is not currently persisted in user preferences, only the URL param allows to persist it at this stage.

Behind :roadmap_settings feature flag.

Fourth iteration of roadmap settings migration.

• First iteration: !78626 (merged)
• Second iteration: !79084 (merged)
• Third iteration: !79302 (merged)

Screenshots or screen recordings

How to set up and validate locally

• Turn on feature flag :roadmap_settings
• Visit a non empty roadmap
• Click on Settings in the top right corner
• A drawer with the Roadmap settings title shows up
• Test Progress tracking radio buttons
• URL gets updated when changing options and epics progress bars are updated.

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

Related to #349739 (closed)