feat(tracing): Add convenience function update_current_span.

[antonpirker]

Manually setting data on spans for our insights modules can be made easier. This PR introduces a convenience function.

Right now users need to do some like this:

import sentry_sdk

span = sentry_sdk.get_current_span()
if span is not None:
    span.description = f"Some {dynamic} name"
    span.set_attribute("key1", "value1")
    span.set_attribute("key2", "value2")

With this new convenience function a user can do:

import sentry_sdk

sentry_sdk.update_current_span(
    name=f"Some {dynamic} name",
    attributes={
        "key1": "value1",
        "key2": "value2",
    },
)

[codecov]

Codecov Report

❌ Patch coverage is 53.33333% with 7 lines in your changes missing coverage. Please review.
✅ Project coverage is 85.07%. Comparing base (63e0c67) to head (c422241).
⚠️ Report is 1 commits behind head on master.
✅ All tests successful. No failed tests found.

Files with missing lines	Patch %	Lines
sentry_sdk/api.py	53.33%	4 Missing and 3 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #4673      +/-   ##
==========================================
+ Coverage   85.02%   85.07%   +0.04%     
==========================================
  Files         156      156              
  Lines       15809    15824      +15     
  Branches     2671     2677       +6     
==========================================
+ Hits        13442    13462      +20     
+ Misses       1586     1583       -3     
+ Partials      781      779       -2     

Files with missing lines	Coverage Δ
sentry_sdk/__init__.py	100.00% <ø> (ø)
sentry_sdk/api.py	86.57% <53.33%> (-3.73%)	⬇️

... and 7 files with indirect coverage changes