Update installation supported OSes

[mDuo13]

• Update the minimum/supported/recommended versions for various supported OSes. Fixes Update install docs for Ubuntu 20.04 end-of-life #3060
• CentOS is no longer supported, so renamed the relevant files to remove mention of CentOS, and added redirects from their old locations.
  • Also added redirects for Japanese, and updated old redirects to go to the new location instead of redirecting to a path that's been redirected again.
• Remove the leading $ from some commandline instructions. People like to copy-paste instructions and this breaks that without adding clarity, so we've moved away from including $ in shell examples (unless the example includes both the command and response, in which case the $ helps to distinguish which is which).
• Update reporting mode page to clarify that Reporting Mode has been removed and to direct people to Clio instead & remove a Reporting Mode diagram that's no longer needed. (Remove rippled Reporting Mode #2957 - doesn't fully fix though)
• Remove some unnecessary frontmatter from the affected files.
• For some reason, the local build started alerting about a missing partial in the PermissionedDomainSet transaction type reference page. This alerted me to an error that must have occurred when migrating Permissioned Domains docs from the opensource.ripple.com repo (add permissioned domain object #3029, 2.4.0 Release Notes and Doc Updates #3008)—both the PermissionedDomain ledger entry page and the PermissionedDomainSet transaction page were supposed to refer to the same snippet, but the snippet wasn't copied over; instead, its contents were pasted into the ledger entry page and the transaction page was left referring to a snippet that didn't exist.
  • I fixed it by adding the snippet and referring to it in both places.
  • Also, I adjusted the snippet not to contain the header itself; that's a minor style thing where snippets should not contain the header because they may need to be included in places with different header levels, and it also makes it harder to accidentally gloss over the snippet while reading the source file that includes it.
• Some other minor corrections and rewordings.

I made minimal updates to some Japanese-translated files to fix some broken links and remove reference to the deleted diagram, but this will still need a more thorough update to the Japanese translations.

Aside: I tried making the "Installation" landing page look nicer (for example, by using the {% xrpl-card %} macro that's used on the References landing page or by using a table) but I wasn't satisfied with any of the results so I decided to set aside those improvements (#2256) for another time.

[maria-robobug]

Added some very minor comments, LGTM!

[amarantha-k]

Reviewed and approving updates made after original approval