Add support including test target platform for Eclipse 2024-03 (v4.31) platform

Checklists

[x] Update LCLS Dep
- [x] Ensure Liberty XSDs are updated
[x] Update LSP4MP?
[x] Update LSP4Jakarta?
[x] Update lsp4e/lsp4j deps?
[x] Update jdtls deps?
[x] Update other Category.xml / feature.xml deps?
Tracking
[x] Milestone - e.g. https://github.com/OpenLiberty/liberty-tools-eclipse/milestone/4
[x] Release Plan - https://github.com/orgs/openLiberty/projects/21 (make sure it includes the Milestone highlights so we can bubble up the most important elements to a broader view of Liberty Tools / DevEx work).
[x] Epic issue (this issue)
Test Level
[x] target platform file (copy from last version, update URLs, Ctrl+Space to populate new versions, try to align version with target Eclipse install like with Mend scan contents)
[x] default level in POM
[x] default level GHA
[x] default level Jenkins
[x] Better to test vs. multiple levels in any of these envs or just one?
Other releng

(See https://github.com/OpenLiberty/liberty-tools-eclipse/wiki/Release-build-process)
[x] Mend/Whitesource scan (see instructions in ci/scans/dependency-only-mend-pom.xml)
[x] Static app scan
[x] Update NOTICE file after dep scan (skipped for next time).
[x] Doc update
[x] Eclipse Marketplace entry
[x] Update CHANGELOG.md. (Try GH 'compare', e.g. this.)