Add PutObject checksums

[klauspost]

Single part, checksums must be done manually for now until we have trailing headers.

For multipart we add CRC32C if we don't already send a checksum and we read the content before sending.

Also serves as test for minio/minio#15433 - but should be backwards compatible.

AWS S3 tests

Single Part

{"args":{"bucketName":"minio-go-test-gyprb0a1v4l9x05q","objectName":"i3d5m60tguye3hkgxe1o3gcijmynm0","opts":"minio.PutObjectOptions{UserMetadata: metadata, Progress: progress}"},"duration":246249,"function":"PutObject(bucketName, objectName, reader,size, opts)","name":"minio-go: testPutObjectWithChecksums","status":"PASS"}

Multipart

These send checksum:
	testPutObjectWithMetadata()
	testPutObjectReadAt()
	testPutObjectsUnknownV2()
	testPutObjectNoLengthV2()

go build functional_tests.go   && ./functional_tests
CHECKSUM: 1yLc4A==
{"args":{"bucketName":"minio-go-test-duyyipdmn2jt2axy","metadata":{"Content-Type":["custom/contenttype"],"X-Amz-Meta-CustomKey":["extra  spaces  in   value"]},"objectName":"zn2pdxznyk6rg46yx2jfifgtemt2u9","opts":"minio.PutObjectOptions{UserMetadata: metadata, Progress: progress}"},"duration":71907,"function":"PutObject(bucketName, objectName, reader,size, opts)","name":"minio-go: testPutObjectWithMetadata","status":"PASS"}
CHECKSUM: 1yLc4A==
{"args":{"bucketName":"minio-go-test-d9smpwyxtqnxcxug","objectContentType":"binary/octet-stream","objectName":"fjuqzickiy94a5i2e1od5exi41bvyh","opts":"objectContentType"},"duration":87869,"function":"PutObject(bucketName, objectName, reader, opts)","name":"minio-go: testPutObjectReadAt","status":"PASS"}
CHECKSUM: 73DecA==
CHECKSUM: 73DecA==
CHECKSUM: 73DecA==
CHECKSUM: 73DecA==
{"args":{"bucketName":"minio-go-test-zlq0e6ayw0hgzmhh","objectName":"minio-go-test-zlq0e6ayw0hgzmhhunique4","opts":"","size":""},"duration":3278,"function":"PutObject(bucketName, objectName, reader,size,opts)","name":"minio-go: testPutObjectsUnknownV2","status":"PASS"}
CHECKSUM: LEgalg==
{"args":{"bucketName":"minio-go-test-f5fssd4wb3opahi0","objectName":"minio-go-test-f5fssd4wb3opahi0unique","opts":"","size":135266304},"duration":46122,"function":"PutObject(bucketName, objectName, reader, size, opts)","name":"minio-go: testPutObjectNoLengthV2","status":"PASS"}	

Seems we are compatible with S3.

[vadmeste]

Few comments

[harshavardhana]

Looks like a nil map crash

{"args":{"bucketName":"minio-go-test-5gemq5a4vzcj1kan","objectName":"d1vjw40g3svlve49qpvwwmpqenud6o"},"duration":15,"function":"GetObject(bucketName, objectName)","name":"minio-go: testGetObjectReadAtFunctionalV2","status":"PASS"}
panic: assignment to entry in nil map

goroutine 1 [running]:
github.com/minio/minio-go/v7.(*Client).putObjectMultipartStreamOptionalChecksum(_, {_, _}, {_, _}, {_, _}, {_, _}, 0x8100000, ...)
	/home/runner/work/minio-go/minio-go/api-put-object-streaming.go:390 +0x163c
github.com/minio/minio-go/v7.(*Client).putObjectMultipartStream(_, {_, _}, {_, _}, {_, _}, {_, _}, 0x8100000, ...)
	/home/runner/work/minio-go/minio-go/api-put-object-streaming.go:51 +0x2fe
github.com/minio/minio-go/v7.(*Client).putObjectCommon(_, {_, _}, {_, _}, {_, _}, {_, _}, 0x8100000, ...)
	/home/runner/work/minio-go/minio-go/api-put-object.go:279 +0x718
github.com/minio/minio-go/v7.(*Client).PutObject(_, {_, _}, {_, _}, {_, _}, {_, _}, 0x8100000, ...)
	/home/runner/work/minio-go/minio-go/api-put-object.go:245 +0x265
main.testGetObjectRanges()
	/home/runner/work/minio-go/minio-go/functional_tests.go:11526 +0x8d5
main.main()
	/home/runner/work/minio-go/minio-go/functional_tests.go:12290 +0x2af

[vadmeste]

LGTM

[klauspost]

Ping @harshavardhana