Use amendment disclaimer & update tx ref intros

[mDuo13]

• Update many, many instances of the old "Requires the ____ amendment" or "Added by the ____ amendment" disclaimers with the new amendment-disclaimer amendment, and same for Japanese. Fixes Migrate old amendment disclaimers to use amendment-disclaimer component #3267.
• Update transaction reference pages to link to the conceptual topics they refer to and phrase their descriptions similarly to each other. Fixes Add links from transaction types to topics #1120
• Move amendment disclaimers to the bottom, rather than top, of the sections they apply to. This helps search results show more relevant summaries.
• Apply minor cleanups to frontmatter, like removing some (not all) instances of the deprecated & unused html: and parent: fields, and making indentation of labels more consistent.
• Fix several cases of status: not_enabled being outdated or missing on pages.
• Extend {% amendment-disclaimer ... /%} component with a mode="updated" option that displays a note that this relevant area was updated, not added, by the relevant amendment. (Note for @tequdev: I added a Japanese translation string based on the existing text for the case where the amendment is already enabled, but not for the case when the amendment hasn't been enabled yet.)
• Make the Pseudo-Transactions landing page a proper index.md and redirect the old URLs (ending in pseudo-transaction-types/pseudo-transaction-types/) to a less redundant path.
• Fix styling of amendment disclaimers as they appear in tables, so that they match the font size and line height of other text in the tables.

[maria-robobug]

LGTM, just some minor comments/suggestions.

[amarantha-k]

Thanks for the updates! lgtm