feat(web): Add session handling implementation

[martinkuba]

Which problem is this PR solving?

Follow up to #4972

Discussed in issue open-telemetry/opentelemetry-js-contrib#2358

Short description of the changes

This adds an implementation of session management for web. It introduces a SessionManager class that is responsible for starting, ending, and persisting sessions.

Type of change

Please delete options that are not relevant.

• New feature (non-breaking change which adds functionality)

How Has This Been Tested?

• unit tests
• example added to examples/opentelemetry-web

Checklist:

• Followed the style guidelines of this project
• Unit tests have been added
• Documentation has been updated

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 95.22%. Comparing base (f85cee1) to head (1b70aa0).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5173      +/-   ##
==========================================
- Coverage   95.24%   95.22%   -0.02%     
==========================================
  Files         315      311       -4     
  Lines        8604     8574      -30     
  Branches     1798     1796       -2     
==========================================
- Hits         8195     8165      -30     
  Misses        409      409              

see 4 files with indirect coverage changes

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[pichlermarc]

looks good overall, just a few questions/nits. 🙂

[github-actions]

This PR is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 14 days.

[github-actions]

This PR is stale because it has been open 60 days with no activity. Remove stale label or comment or this will be closed in 14 days.

[pichlermarc]

@martinkuba friendly ping 🙂
Trying to figure out if there's still appetite to land this feature 🤔

[martinkuba]

Hi @pichlermarc, yes, this is still something that I want to see to completion. I have put it temporarily on hold while we are trying to spin up a new SIG for browser instrumentation/API (see open-telemetry/community#2751). In any case, I am planning to come back to this in the near future.

[pichlermarc]

Just some small comments from my side - but overall looks good to merge. 🙌

[pichlermarc]

Looks good, one more commment around using factory functions instead.
I'll wait for the other conversations on the PR to be resolved before merging. Please feel free to ping me when you're ready.