Added support for AWS Sigv4 for UrlLib3.

[dblock]

Description

• Adds SigV4 support for Urllib3HttpConnection.
• Deprecates AWSV4SignerAuth in favor of RequestsAWSV4SignerAuth
• Uses Urllib3AWSV4SignerAuth in the documentation since that transport is faster.

Testing

AOS

export SERVICE=es
export ENDPOINT=https://xyz.us-west-2.aoss.amazonaws.com
poetry run python sigv4/urllib3-hello.py 

INFO:Found credentials in environment variables.
INFO:GET https://search-dblock-test-opensearch-27-xyz.us-west-2.es.amazonaws.com:443/ [status:200 request:0.768s]
opensearch: 2.7.0
INFO:PUT https://search-dblock-test-opensearch-27-xyz.us-west-2.es.amazonaws.com:443/movies [status:200 request:2.298s]
INFO:PUT https://search-dblock-test-opensearch-27-xyz.us-west-2.es.amazonaws.com:443/movies/_doc/1 [status:201 request:0.500s]
INFO:POST https://search-dblock-test-opensearch-27-xyz.us-west-2.es.amazonaws.com:443/_search [status:200 request:0.213s]
{'director': 'Bennett Miller', 'title': 'Moneyball', 'year': 2011}
INFO:DELETE https://search-dblock-test-opensearch-27-xyz.us-west-2.es.amazonaws.com:443/movies/_doc/1 [status:200 request:0.108s]
INFO:DELETE https://search-dblock-test-opensearch-27-xyz.us-west-2.es.amazonaws.com:443/movies [status:200 request:0.223s]

AOSS

export SERVICE=aoss
export ENDPOINT=https://xyz.us-west-2.aoss.amazonaws.com
poetry run python sigv4/urllib3-hello.py 

INFO:Found credentials in environment variables.
INFO:PUT https://xyz.us-west-2.aoss.amazonaws.com:443/movies [status:200 request:4.173s]
INFO:PUT https://xyz.us-west-2.aoss.amazonaws.com:443/movies/_doc/1 [status:201 request:3.117s]
INFO:POST https://xyz.us-west-2.aoss.amazonaws.com:443/_search [status:200 request:4.916s]
{'director': 'Bennett Miller', 'title': 'Moneyball', 'year': 2011}
INFO:DELETE https://xyz.us-west-2.aoss.amazonaws.com:443/movies/_doc/1 [status:200 request:1.249s]
INFO:DELETE https://xyz.us-west-2.aoss.amazonaws.com:443/movies [status:200 request:0.168s]

Issues Resolved

Closes https://github.com/opensearch-project/opensearch-py/issues/546

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license. For more information on following Developer Certificate of Origin and signing off your commits, please check here.

[codecov[bot]]

Codecov Report

Merging #547 (284a5fd) into main (fa8f3a7) will increase coverage by 0.02%. The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #547      +/-   ##
==========================================
+ Coverage   70.63%   70.66%   +0.02%     
==========================================
  Files          83       83              
  Lines        7857     7877      +20     
==========================================
+ Hits         5550     5566      +16     
- Misses       2307     2311       +4     

Files	Coverage Δ
opensearchpy/__init__.py	92.85% <100.00%> (ø)
opensearchpy/connection/http_urllib3.py	82.00% <100.00%> (-4.03%)	:arrow_down:
opensearchpy/helpers/__init__.py	100.00% <100.00%> (ø)
opensearchpy/helpers/signer.py	98.03% <100.00%> (+3.30%)	:arrow_up:

... and 2 files with indirect coverage changes

[dblock]

@harshavamsi would appreciate your CR since you did support for the requests connection class.

[dblock]

@VachaShah I wrote some more tests and addressed your comments. LMK if there's anything else needed for this one