fix: copy source maps for frontend resources

[vursen]

Description

This PR fixes TaskCopyFrontendFiles so that it copies source maps for frontend resources as well.

Related to #12574

Type of change

• Bugfix

Checklist

• I have read the contribution guide: https://vaadin.com/docs/latest/guide/contributing/overview/
• I have added a description following the guideline.
• The issue is created in the corresponding repository and I have referenced it.
• I have added tests to ensure my change is effective and works as intended.
• New and existing tests are passing locally with my change.
• I have performed self-review and corrected misspellings.

[CLAassistant]

All committers have signed the CLA.

[github-actions]

Unit Test Results

   769 files  ±0     769 suites  ±0   24m 11s ⏱️ +2s
5 742 tests ±0  5 690 ✔️  - 1  52 💤 +1  0 ❌ ±0 
5 774 runs   - 4  5 721 ✔️  - 5  53 💤 +1  0 ❌ ±0 

Results for commit 7569e03. ± Comparison against base commit bcf4b12.

♻️ This comment has been updated with latest results.

[sonarcloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

No Coverage information
0.0% Duplication

[platosha]

LGTM 👍

I’d suggest that we also merge this in 2.7, 2.8 and 9.0 branches, as this is something potentially useful with webpack (and source-map-loader) also.

Added the target/... labels here for automatic cherry picking.

[vaadin-bot]

Hi @vursen and @vursen, when i performed cherry-pick to this commit to 2.8, i have encountered the following issue. Can you take a look and pick it manually?
Error Message:
Error: Command failed: git cherry-pick 2eaf26f
error: could not apply 2eaf26f... fix: copy source maps for frontend resources (#12701)
hint: after resolving the conflicts, mark the corrected paths
hint: with 'git add ' or 'git rm '
hint: and commit the result with 'git commit'

[vaadin-bot]

Hi @vursen and @vursen, when i performed cherry-pick to this commit to 2.7, i have encountered the following issue. Can you take a look and pick it manually?
Error Message:
Error: Command failed: git cherry-pick 2eaf26f
error: could not apply 2eaf26f... fix: copy source maps for frontend resources (#12701)
hint: after resolving the conflicts, mark the corrected paths
hint: with 'git add ' or 'git rm '
hint: and commit the result with 'git commit'

[vaadin-bot]

This ticket/PR has been released with platform 23.0.0.alpha3 and is also targeting the upcoming stable 23.0.0 version.