[ENHANCEMENT] EChart: extract timezone-aware axis label formatter

[andreasgerstmayr]

Description

Extract timezone-aware axis label formatter

This util is currently duplicated in the timeseries, scatter, heaptmap and statushistory charts:
https://github.com/perses/plugins/blob/39a7700a8fd33c1539a1af12b828db35bcdd91d0/timeserieschart/src/utils/timezone-formatter.ts
https://github.com/perses/plugins/blob/39a7700a8fd33c1539a1af12b828db35bcdd91d0/heatmapchart/src/utils/get-formatted-axis-label.ts
https://github.com/perses/plugins/blob/39a7700a8fd33c1539a1af12b828db35bcdd91d0/statushistorychart/src/utils/get-formatted-axis-label.ts
perses/plugins#712

Screenshots

no changes

Checklist

• Pull request has a descriptive title and context useful to a reviewer.
• Pull request title follows the [<catalog_entry>] <commit message> naming convention using one of the
  following catalog_entry values: FEATURE, ENHANCEMENT, BUGFIX, BREAKINGCHANGE, DOC,IGNORE.
• All commits have DCO signoffs.

UI Changes

• Changes that impact the UI include screenshots and/or screencasts of the relevant changes.
• Code follows the UI guidelines.
• E2E tests are stable and unlikely to be flaky.
  See e2e docs for more details. Common issues include:
  • Is the data inconsistent? You need to mock API requests.
  • Does the time change? You need to use consistent time values or mock time utilities.
  • Does it have loading states? You need to wait for loading to complete.