Add javax.inject/annotation provided by Jakarta from Maven-Central and include all sources in Eclipse SDK repo

[HannesWell]

Use the javax namespace bundles provided by Jakarta.
Remove all javax bundles provided by Orbit.

Remove the unused javax.xml bundle, the modern JREs provide the contained packages by default.

Part of #1056

Additionally configure the tycho-p2-repository-plugin to include all sources. This allows to remove the javax-bundles from containing features (see eclipse-platform/eclipse.platform.ui#745) and at the same time to keep the main artifacts (which are pulled in as transitive dependencies) plus their sources in the created p2-repo for the Eclipse SDK.

[HannesWell]

For now I changed this PR to only add the jakarta-bundles because of eclipse-platform/eclipse.platform.common#145 (comment).

The removal of the javax-bundles will happen in a follow up, after a nightly build.

[HannesWell]

Comparing the produced content.xml with the one from the master branch, it looks like the javax.inject/annotation bundles provided by jakarta (but with javax-namespace) are added to the I-builds repo as desired:

<unit id="jakarta.annotation-api" version="1.3.5" singleton="false" generation="2">
<unit id="jakarta.annotation-api.source" version="1.3.5" singleton="false">
<unit id="jakarta.inject.jakarta.inject-api" version="1.0.5" singleton="false" generation="2">
<unit id="jakarta.inject.jakarta.inject-api.source" version="1.0.5" singleton="false">

Therefore I merge this so that the mentioned bundles are available in the repo tomorrow and I can continue the migration.

[HannesWell]

Btw. @akurtakov, @merks, @laeubi with configuring the tycho-p2-repository-plugin with includeAllSources=true, we could actually start to remove more third party-bundles from features.

In the last discussion about removing them, then main argument to leave them in was that this way it is ensured that the sources are included into the p2-repo and therefore available without any further magic (like m2e).
With that change the mentioned bundles will get their sources included into the repo even if only pulled in as transitive dependency.
If we remove them we can save us enforced qualifier updates in the features if a version is updated or adaptions to BSN changes.

[merks]

Yes the force qualifier updates changes are a pain in the neck. The cbi aggregator also aggregates corresponding source bundles for every bundle otherwise aggregated so this would continue to work well for SimRel.

[laeubi]

If the bundle is from maven (central) and m2e is available the sources should even be downloaded if not in the update-site.