Improved proto conversion quality and tests

[jmwilliams89]

Description of Changes

• Improves the readability of the google protobuf conversion code
• Improves the error messages in the google protobuf conversion code
• Increases test coverage back to 100% for the google cloud operator

Please check that the PR fulfills these requirements

• Tests for the changes have been added (for bug fixes / features)
• Docs have been added / updated (for bug fixes / features)
• Add a changelog entry (for non-trivial bug fixes / features)
• CI passes

[djaglowski]

Log Files	Logs / Second	CPU Avg (%)	CPU Avg Δ (%)	Memory Avg (MB)	Memory Avg Δ (MB)
1	1000	1.6379322	-0.06898117	130.05307	-3.556839
1	5000	5.896637	+0.051618576	135.60156	+1.119339
1	10000	11.7244	+0.034309387	146.12096	+0.7522888
1	50000	64.84864	-1.1692505	178.39655	+4.5149384
1	100000	127.4824	-7.420143	244.22656	+15.338638
10	100	1.9827615	-0.25864327	134.64035	-0.87190247
10	500	7.241595	+0.3277979	140.72832	-3.5604706
10	1000	12.931432	-0.17222404	147.93158	+3.740448
10	5000	66.898674	-5.1030884	177.52586	-0.95555115
10	10000	134.32707	-0.45343018	226.07126	-11.815994

[codecov]

Codecov Report

Merging #511 (57c40d7) into master (3140581) will increase coverage by 0.19%.
The diff coverage is 100.00%.

❗ Current head 57c40d7 differs from pull request most recent head 8ca6f60. Consider uploading reports for the commit 8ca6f60 to get more accurate results

@@            Coverage Diff             @@
##           master     #511      +/-   ##
==========================================
+ Coverage   76.41%   76.59%   +0.19%     
==========================================
  Files         132      132              
  Lines        8290     8301      +11     
==========================================
+ Hits         6334     6358      +24     
+ Misses       1484     1476       -8     
+ Partials      472      467       -5     

Impacted Files	Coverage Δ
operator/builtin/output/googlecloud/entry.go	100.00% <100.00%> (ø)
operator/builtin/output/googlecloud/proto.go	100.00% <100.00%> (+13.98%)	⬆️

---

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 3140581...8ca6f60. Read the comment docs.

[cpheps]

LGTM

[djaglowski]

Log Files	Logs / Second	CPU Avg (%)	CPU Avg Δ (%)	Memory Avg (MB)	Memory Avg Δ (MB)
1	1000	1.8103356	+0.103422284	130.23962	-3.370285
1	5000	7.051867	+1.2068486	139.61018	+5.12796
1	10000	11.500452	-0.18963814	144.48666	-0.8820038
1	50000	62.34609	-3.6718025	177.44504	+3.5634308
1	100000	127.93152	-6.9710236	237.58028	+8.692352
10	100	2.0517328	-0.189672	132.89333	-2.618927
10	500	6.9311385	+0.017341614	139.24232	-5.046463
10	1000	12.776115	-0.3275404	148.35117	+4.160034
10	5000	67.60459	-4.397171	177.94478	-0.53663635
10	10000	151.05055	+16.27005	244.1281	+6.2408447