Add effective dates to ToU and HP pages and fix versions panel

[dati18]

• Add Effective date in the subheader of the HP and ToU pages
• In the policy navigation panel, the ToU versions' titles are formatted to <DD Month YYYY> (current) (e.g., 1 January 2022 (current) or 1 January 2021, not Current version or 2021-01-01)

Bug: T434191

[github-actions]

Deployment previews on netlify for branch refs/pull/1167/merge will be at the following locations (when build is done):

• UI with mock store: https://b4f5d109ea-mock--wbstack-ui.netlify.app/
• UI pointing to prod: https://b4f5d109ea-prod--wbstack-ui.netlify.app/

[outdooracorn]

Sorry this took so long for me to review. I had to remind myself how JavaScript/Vue works and all the Policy code is gnarly. 😅

• From my local testing, and review of the code, these changes look correct.
• I've left some minor suggestions for improvements to the title (heading and subheading).
• There are still some things that don't align with the design and the task's A/C includes UI matches design specs:
  • "previous version" in "What changed from the previous version" is the only part that should be linked (i.e. move "the" to outside the router-link tag).
  • "previous version" should also be underlined. I'm not sure why the router-link tag has a text-decoration-none Vuetify2 CSS class, but the designs suggest that this should be removed.
  • The of in "Terms of Use" title should be lower-case.
  • There are also some other things that I noticed, but I don't think they really belong to T434191, so I'll write them elsewhere. For future learning, "UI matches design specs" is probably too vague an A/C for this type of specific task (I've updated the task to be more specific, so the scope of this task doesn't creep).

You could make these changes in this PR or in one or more follow-up PRs. I've approved this PR to enable that flexibility as it correctly does what it says.

[outdooracorn]

Gahh! I always think suggestions will be helpful, and then they never quite apply as you think they will :/

[outdooracorn]

Approving to get this merged and unblock other work. The other issues noted in my comment can be addressed in a follow-up.