feat(logger): add get_correlation_id method

[michaelbrewer]

Issue #, if available:

• https://github.com/awslabs/aws-lambda-powertools-python/issues/518

Description of changes:

• Call remove_keys["correlation_id"] when the correlation_id is set to None.
• Add get_correlation_id call

from aws_lambda_powertools import Logger

logger = Logger()
logger.set_correlation_id("Foo")
assert "Foo" == logger.get_correlation_id()
logger.set_correlation_id(None)
assert logger.get_correlation_id() is None

Checklist

• Meet tenets criteria
• Update tests
• Update docs
• PR title follows conventional commit semantics

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of your choice.

[codecov-commenter]

Codecov Report

Merging #516 (3630d1d) into develop (5b87bb1) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff            @@
##           develop     #516   +/-   ##
========================================
  Coverage    99.23%   99.23%           
========================================
  Files          113      113           
  Lines         4468     4472    +4     
  Branches       243      244    +1     
========================================
+ Hits          4434     4438    +4     
  Misses          22       22           
  Partials        12       12           

Impacted Files	Coverage Δ
aws_lambda_powertools/logging/logger.py	100.00% <100.00%> (ø)

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[Nr18]

LGTM ;-)

[michaelbrewer]

@heitorlessa should we go ahead with this feature?

[heitorlessa]

I've just added a comment in the RFC.

TL;DR: Definitely yes for Getter, perhaps even a generic one to grab any key. Not yet for the remove correlation ID method.

[heitorlessa]

By default, Logger removes any key with None value before emitting a log entry.

[michaelbrewer]

@heitorlessa made the changes. the diff is much more minimal, but still meet the needs of the original RFC

[heitorlessa]

Thanks a lot again @michaelbrewer !