Add mithril-client-wasm tests in multi platform test

[dlachaume]

Content

This PR includes tests implementation for mithril-client-wasm. This tests are executed in headless mode with Google Chrome and Firefox from the manual workflow Mithril Client multi-platform test.

Two scripts were added:

• run-wasm-tests-browser-headless.py: call by the manual workflow to run browsers in headless mode and save the output to a html file with the test results. It takes the browser as argument (chrome or firefox).
• parse-wasm-headless-tests-results.sh: call by the manual workflow to handle both browsers test results

Pre-submit checklist

• Branch
  • Tests are provided (if possible)
  • Crates versions are updated (if relevant)
  • Commit sequence broadly makes sense
  • Key commits have useful messages
• PR
  • No clippy warnings in the CI
  • Self-reviewed the diff
  • Useful pull request description
  • Reviewer requested
• Documentation
  • Update README file (if relevant)
  • Update documentation website (if relevant)
  • Add dev blog post (if relevant)

Issue(s)

Close to #1408

[github-actions]

Test Results

  3 files  ±0   33 suites  ±0   8m 38s ⏱️ -5s
787 tests ±0  787 ✅ ±0  0 💤 ±0  0 ❌ ±0 
860 runs  ±0  860 ✅ ±0  0 💤 ±0  0 ❌ ±0 

Results for commit 153c91f. ± Comparison against base commit ec8910b.

♻️ This comment has been updated with latest results.

[jpraynaud]

LGTM 👍