BundleComponent.isValidBundle() should no throw if reading manifest fail

[laeubi]

Currently BundleComponent.isValidBundle() is used to check if a bundle is valid and should be considered for the baseline. If the location points to something that chase no manifest at all (or an invalid manifest) this currently an exception even though the API doc clearly states that "Validity is determined via the existence of a readable manifest file"

This now adds two checks

1) the location points to a file that exits and is larger than zero bytes 2) parsing the manifest from the location do not throw an exception

This error can be seen for example here: https://ci.eclipse.org/equinox/job/p2/job/PR-524/8/console

[laeubi]

/request-license-review

[github-actions[bot]]

Test Results

   291 files  ±0     291 suites  ±0   1h 1m 20s :stopwatch: + 2m 2s  3 578 tests ±0   3 502 :white_check_mark: +2   76 :zzz: ±0  0 :x: ±0  11 031 runs  ±0  10 800 :white_check_mark: +2  231 :zzz: ±0  0 :x: ±0 

Results for commit 2773e25b. ± Comparison against base commit 93f76cf6.

:recycle: This comment has been updated with latest results.

[github-actions[bot]]

/request-license-review

License review requests:

• p2/orbit/p2.eclipse.plugin/org.hamcrest.core/2.2.0.v20230809-1000

After all reviews have concluded, re-run the license-vetting check from the Github Actions web-interface to update its status.

Workflow run (with attached summary files): https://github.com/eclipse-pde/eclipse.pde/actions/runs/9536767493