Big bundle of tweaks to get 3.3 to build

[Swiddis]

Description

Lots of hacky changes, going to be adding some docs and seeing what it'd take to finalize these. Let's merge these initial fixes quickly and figure out long-term changes later.

Exact list of changes:

• Updated Sonatype location to new S3 repository
• Changed the default version from 3.1 to 3.3 (TODO: auto-use the latest)
• Locks the opensearch-java client version to 3.2 (should be independent of OS since it's a client, and it causes issues to keep it in sync since it has a different release cadence).
• Implements a new RestClientImpl method (since it was added to the interface in SQL)
• Fixes some mismatches with some sources expecting 4 digits in a version (SQL plugin jars all need 3_3_0_0) while others need 3 digits (org.opensearch:opensearch needs 3.3.0)
• Link updates (for Lychee), @vamsimanohar's username change continues to be annoying ;)

For the long term, we need to:

• Remove hardcoded references to 3.3, just use the latest version by default
• Figure out some sort of tests to lock our SQL interfaces in place (such as the ClientImpl here)

Issues Resolved

CLI doesn't build with 3.3

Check List

• New functionality includes testing.
  • All tests pass, including unit test, integration test and doctest
• New functionality has been documented.
  • New functionality has javadoc added
  • New functionality has user manual doc added
• Commits are signed per the DCO using --signoff

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