Add flag to fail API tools on resolution error

[Kummallinen]

Add failOnResolutionError to api-tools configuration, when true it will fail the build if the baseline repository does not correctly resolve. Default to false to maintain existing behaviour, though 'true' is probably the preferred behaviour for many users.

Also adds tests to tycho-its for this

Fixes #3570

[Kummallinen]

Windows test failure seems unrelated to my change, looks like an unreliable test:
TestPGPSigning.testSigningBinaries:251 Unexpected unsigned IUs. ==> expected: <[org.eclipse.equinox.common, org.eclipse.equinox.common.source, org.eclipse.osgi, org.eclipse.osgi.source]> but was: <[org.eclipse.equinox.common, org.eclipse.osgi, org.eclipse.osgi.source]>

[github-actions]

Test Results

  594 files    594 suites   4h 33m 5s ⏱️
  418 tests   410 ✅  7 💤 1 ❌
1 254 runs  1 231 ✅ 22 💤 1 ❌

For more details on these failures, see this check.

Results for commit 7cc3434.

[eclipse-tycho-bot]

💚 All backports created successfully

Status	Branch	Result
✅	tycho-4.0.x

Note: Successful backport PRs will be merged automatically after passing CI.

Questions ?

Please refer to the Backport tool documentation and see the Github Action logs for details

[laeubi]

@Kummallinen thanks for providing this new option and testcases.

[Kummallinen]

@laeubi thank you for the review, merge & backport