chore: Add support for push sources in feature views

[achals]

Signed-off-by: Achal Shah [email protected]

What this PR does / why we need it:
Part 2 after #2428

Which issue(s) this PR fixes:

Fixes #

[codecov-commenter]

Codecov Report

Merging #2452 (0a42623) into master (3db4b1b) will increase coverage by 0.12%.
The diff coverage is 91.17%.

@@            Coverage Diff             @@
##           master    #2452      +/-   ##
==========================================
+ Coverage   84.72%   84.85%   +0.12%     
==========================================
  Files         126      127       +1     
  Lines       10798    10833      +35     
==========================================
+ Hits         9149     9192      +43     
+ Misses       1649     1641       -8     

Flag	Coverage Δ
integrationtests	75.15% <91.04%> (+0.19%)	⬆️
unittests	58.31% <55.88%> (-0.13%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
sdk/python/feast/repo_operations.py	55.05% <33.33%> (-0.34%)	⬇️
sdk/python/feast/feature_view.py	91.47% <77.77%> (-1.22%)	⬇️
sdk/python/feast/data_source.py	66.98% <85.71%> (+1.28%)	⬆️
sdk/python/feast/__init__.py	90.90% <100.00%> (ø)
sdk/python/feast/feature_store.py	91.65% <100.00%> (+0.09%)	⬆️
...ts/integration/feature_repos/repo_configuration.py	96.10% <100.00%> (+0.02%)	⬆️
...tegration/feature_repos/universal/feature_views.py	84.61% <100.00%> (+0.74%)	⬆️
...gration/online_store/test_push_online_retrieval.py	100.00% <100.00%> (ø)
.../python/tests/integration/registration/test_cli.py	98.72% <100.00%> (ø)
sdk/python/tests/unit/test_data_sources.py	100.00% <100.00%> (ø)
... and 6 more

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 3db4b1b...0a42623. Read the comment docs.

[felixwang9817]

looks good overall - at some point we should add (a) docs for PushSource and (b) deprecation warning for write_to_online_store, happy for those to be in future PR - up to you

[felixwang9817]

some more nits

[felixwang9817]

/lgtm

[feast-ci-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: achals, felixwang9817

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

• OWNERS [achals,felixwang9817]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment