GODRIVER-3898 Move the FindAndModify logic into the "mongo" package.

[qingyang-hu]

GODRIVER-3898

Summary

Move the FindAndModify logic into the "mongo" package.

Background & Motivation

[mongodb-drivers-pr-bot]

API Change Report

./v2/x/mongo/driver/operation

incompatible changes

FindAndModify: removed
FindAndModifyResult: removed
LastErrorObject: removed
NewFindAndModify: removed

[mongodb-drivers-pr-bot]

🧪 Performance Results

Commit SHA: 30b14b6

The following benchmark tests for version 6a692f9792db270007521678 had statistically significant changes (i.e., |z-score| > 1.96):

Benchmark	Measurement	% Change	Patch Value	Stable Region	H-Score	Z-Score
BenchmarkMultiFindMany	ops_per_second_min	-87.3009	4615.8462	Avg: 36347.9624 Med: 37475.7887 Stdev: 15184.1831	0.7272	-2.0898
BenchmarkBSONFlatDocumentEncoding	ops_per_second_min	-45.8643	2043.9573	Avg: 3775.6203 Med: 3904.8760 Stdev: 655.1074	0.8305	-2.6433
BenchmarkMultiInsertSmallDocument	ns_per_op	-6.5540	5906.0000	Avg: 6320.2260 Med: 6311.5000 Stdev: 168.1147	0.7830	-2.4639
BenchmarkBSONFlatDocumentDecoding	total_mem_allocs	6.1294	11177914.0000	Avg: 10532346.5691 Med: 10565554.0000 Stdev: 238082.7894	0.7950	2.7115
BenchmarkBSONFlatDocumentDecoding	total_bytes_allocated	6.1176	439553848.0000	Avg: 414213957.9837 Med: 415515656.0000 Stdev: 9349912.2152	0.7949	2.7102
BenchmarkSingleFindOneByID	ops_per_second_med	5.8459	4503.1860	Avg: 4254.4719 Med: 4249.6499 Stdev: 112.7547	0.7565	2.2058
BenchmarkSingleFindOneByID	ns_per_op	-5.8406	227728.0000	Avg: 241853.6359 Med: 241932.0000 Stdev: 6890.5348	0.7385	-2.0500
BenchmarkBSONFlatDocumentDecoding	ops_per_second_max	5.4877	22552.9995	Avg: 21379.7333 Med: 21377.1137 Stdev: 345.9938	0.8368	3.3910
BenchmarkBSONFlatDocumentDecoding	ops_per_second_med	5.0167	21581.0260	Avg: 20550.0906 Med: 20562.1697 Stdev: 418.3983	0.7766	2.4640
BenchmarkBSONFullDocumentDecoding	ns_per_op	-4.8625	70314.0000	Avg: 73907.7281 Med: 73614.0000 Stdev: 1561.9554	0.7649	-2.3008
BenchmarkBSONFullDocumentDecoding	total_bytes_allocated	4.6407	429891240.0000	Avg: 410825967.8525 Med: 411800528.0000 Stdev: 8795072.6696	0.7480	2.1677
BenchmarkBSONFullDocumentDecoding	total_mem_allocs	4.6179	10387599.0000	Avg: 9929079.7880 Med: 9954253.0000 Stdev: 211401.3514	0.7485	2.1690
BenchmarkBSONFullDocumentDecoding	ops_per_second_med	4.6087	15228.3491	Avg: 14557.4377 Med: 14585.7643 Stdev: 272.5229	0.7814	2.4619
BenchmarkBSONFullDocumentDecoding	ops_per_second_max	4.0431	15788.8089	Avg: 15175.2578 Med: 15165.7618 Stdev: 187.6260	0.8437	3.2701
BenchmarkMultiFindMany	ops_per_second_max	3.6537	4385964.9123	Avg: 4231365.4958 Med: 4237288.1356 Stdev: 50902.8922	0.8272	3.0371
BenchmarkBSONDeepDocumentEncoding	total_time_seconds	-2.9943	1.1578	Avg: 1.1935 Med: 1.1940 Stdev: 0.0094	0.8642	-3.7915
BenchmarkBSONFullDocumentEncoding	ops_per_second_max	2.3388	48381.6343	Avg: 47275.9560 Med: 47307.0485 Stdev: 530.0318	0.7519	2.0861
BenchmarkBSONFlatDocumentDecoding	allocated_bytes_per_op	-0.0124	18050.0000	Avg: 18052.2396 Med: 18052.0000 Stdev: 0.9466	0.8019	-2.3660

For a comprehensive view of all microbenchmark results for this PR's commit, please check out the Evergreen perf task for this patch.