fix: moved JSR356 atmosphere parameters set to PushRequestHandler

[MarcinVaadin]

Description

Moved setting JSR356 url mapping parameters to PushRequestHandler. Supports both SpringServlet and VaadinServlet parameters.

pushURL does not work with custom contextPath.

Fixes #14641

Type of change

• [x] Bugfix
• [x] Feature

Checklist

• [x] I have read the contribution guide: https://vaadin.com/docs/latest/guide/contributing/overview/
• [x] I have added a description following the guideline.
• [x] 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.
• [x] New and existing tests are passing locally with my change.
• [x] I have performed self-review and corrected misspellings.

Additional for Feature type of change

• [x] Enhancement / new feature was discussed in a corresponding GitHub issue and Acceptance Criteria were created.

[github-actions[bot]]

Unit Test Results

   955 files  ±0     955 suites  ±0   47m 33s :stopwatch: - 1m 14s 6 083 tests ±0  6 029 :heavy_check_mark: ±0  54 :zzz: ±0  0 :x: ±0  6 347 runs  ±0  6 285 :heavy_check_mark: ±0  62 :zzz: ±0  0 :x: ±0 

Results for commit f69f5ccd. ± Comparison against base commit 61ac6e6f.

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

[sonarqubecloud[bot]]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
4 Code Smells

No Coverage information
No Duplication information

[mshabarov]

Closed in favour of https://github.com/vaadin/flow/pull/15188