[FIX] website: update table of content navbar when heading style changes

[fw-bot]

Steps to reproduce:

1. Enable a second language on the website
2. Add a Table of Content snippet to a page
3. Apply bold (or any inline style) to one of the headings, save
4. Switch to the second language in translation mode
5. Translate the styled heading and save

=> The TOC navbar entry keeps showing the source text on reload.
=> Expected: navbar shows the translated heading text, unstyled.

Cause:

When a TOC heading carries inline markup, the server emits the
heading and the navbar entry as two independent translation terms
with different data-oe-translation-source-sha values, even though
their textContent matches. A translation written under the heading's
sha therefore never reaches the navbar's slot.

handleToC was meant to bridge that by aliasing the navbar span's
sha to the heading's during translation-mode setup, but two issues
prevented it from working in saas-18.4+:

• The TOC navbar lives under .o_not_editable, so its translation
  spans were excluded from findOEditable and handleToC never
  ran on them. The class o_translation_without_style was never
  added, and the sha was never aliased.

Solution:

• prepareTranslation iterates TOC navbar translation spans
  explicitly, so handleToC reaches them despite findOEditable
  skipping .o_not_editable.
• handleToC always tags the navbar span with
  o_translation_without_style when a matching heading exists.
• An after_replication_handlers hook flags every replicated
  unstyled-translation target as .o_dirty, so the replicated
  translation is included in the save.

opw-5950228

Forward-Port-Of: #263547
Forward-Port-Of: #260378

[robodoo]

[fw-bot]

@sben-odoo @robinlej cherrypicking of pull request #260378 failed.

stdout:

Auto-merging addons/website/static/src/builder/plugins/translation/translation_plugin.js
CONFLICT (content): Merge conflict in addons/website/static/src/builder/plugins/translation/translation_plugin.js
Auto-merging addons/website/static/tests/builder/translation.test.js

Either perform the forward-port manually (and push to this branch, proceeding as usual) or close this PR (maybe?).

you can use git-fw to re-do the forward-port for you locally.

⚠️ after resolving this conflict, you will need to merge it via @robodoo.

More info at https://github.com/odoo/odoo/wiki/Mergebot#forward-port

[fw-bot]

@sben-odoo @robinlej this forward port of #260378 is awaiting action (not merged or closed).

[sben-odoo]

robodoo r+