S3 API: Add SSE-C (#7143)

* implement sse-c

* fix Content-Range

* adding tests

* Update s3_sse_c_test.go

* copy sse-c objects

* adding tests

* refactor

* multi reader

* remove extra write header call

* refactor

* SSE-C encrypted objects do not support HTTP Range requests

* robust

* fix server starts

* Update Makefile

* Update Makefile

* ci: remove SSE-C integration tests and workflows; delete test/s3/encryption/

* s3: SSE-C MD5 must be base64 (case-sensitive); fix validation, comparisons, metadata storage; update tests

* minor

* base64

* Update SSE-C_IMPLEMENTATION.md

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

* Update weed/s3api/s3api_object_handlers.go

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

* Update SSE-C_IMPLEMENTATION.md

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

* address comments

* fix test

* fix compilation

---------

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

.gitignore

@@ -116,3 +116,4 @@ test/s3/versioning/weed-test.log
 docker/agent_pub_record
 docker/admin_integration/weed-local
 /seaweedfs-rdma-sidecar/bin
+/test/s3/encryption/filerldb2