Add support for Eclipse 2023-06 (v4.28) platform

[scottkurz]

Checklists

(From https://github.com/OpenLiberty/liberty-tools-eclipse/wiki/Fix-Release-Checklist)

Dependencies

• [x] Update LCLS Dep (upgrade to v2.0.1)
• [x] Update LSP4MP? (no, remain on v0.7)
• [x] Update LSP4Jakarta? (no, remain on v0.1.1)
• [x] Update lsp4e/lsp4j deps?
• [x] Update jdtls deps?
• [x] Update other Category.xml / feature.xml deps?

  Tracking

• [x] Release Plan - https://github.com/orgs/openLiberty/projects/21
• [x] Milestone - https://github.com/OpenLiberty/liberty-tools-eclipse/milestone/4
• [x] Epic

  Test Level

• [x] target platform file
• [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?
• [x] Test LCLS 2.0.1 delta

  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] Doc updates
• [x] Update changelog