fix: prevent style leaking with exported webcomponents

[mcollovati]

No description provided.

[mcollovati]

This is an experimental attempt to try to fix some exported web-components issues:

• styles leaking in the embedding document
• styles leaking between web-components from different applications
• JavaScript import errors when embedding from different applications

Related to #19700

[github-actions]

Test Results

  589 files   -   539    589 suites   - 539   1h 9m 19s ⏱️ - 11m 57s
1 015 tests  - 6 292    980 ✅  - 6 277  35 💤  - 15  0 ❌ ±0 
1 339 runs   - 6 295  1 294 ✅  - 6 280  45 💤  - 15  0 ❌ ±0 

Results for commit f9920ce. ± Comparison against base commit f81d6bd.

This pull request removes 6293 and adds 1 tests. Note that renamed tests count towards both.

com.vaadin.AssertionTest ‑ testAssertionsAreEnabled
com.vaadin.base.devserver.AbstractDevServerRunnerTest ‑ shouldPassEncodedUrlToDevServer
com.vaadin.base.devserver.AbstractDevServerRunnerTest ‑ updateServerStartupEnvironment_preferIpv4_LocalhostIpAddressAddedToProcessEnvironment
com.vaadin.base.devserver.AbstractDevServerRunnerTest ‑ updateServerStartupEnvironment_preferIpv6_LocalhostIpAddressAddedToProcessEnvironment
com.vaadin.base.devserver.BrowserLiveReloadAccessorImplTest ‑ getLiveReload_devMode_contextHasNoReloadInstance_instanceIsCreated
com.vaadin.base.devserver.BrowserLiveReloadAccessorImplTest ‑ getLiveReload_devMode_contextHasReloadInstance_instanceIsReturned
com.vaadin.base.devserver.BrowserLiveReloadAccessorImplTest ‑ getLiveReload_liveReloadDisabled_instanceIsCreated
com.vaadin.base.devserver.BrowserLiveReloadAccessorImplTest ‑ getLiveReload_productionMode_nullIsReturned
com.vaadin.base.devserver.DebugWindowConnectionTest ‑ backwardsCompatibilityClassExists
com.vaadin.base.devserver.DebugWindowConnectionTest ‑ getBackend_HotSwapVaadinIntegrationClassLoaded_returnsHOTSWAP_AGENT
…

com.vaadin.flow.webcomponent.ApplicationThemeComponentIT ‑ cssImportAnnotation_doNotLeakEmbeddingPage[any_Chrome_]

♻️ This comment has been updated with latest results.

[mcollovati]

It looks like this experiment is breaking everything

EDIT: failures were caused by a missing import in flow generated imports file.

[sonarcloud]

Quality Gate passed

Issues
13 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud