* handle HTTP PATCH requests as logical.PatchOperation
* update go.mod, go.sum
* a nil response for logical.PatchOperation should result in 404
* respond with 415 for incorrect MIME type in PATCH Content-Type header
* add abstraction to handle PatchOperation requests
* add ACLs for patch
* Adding JSON Merge support to the API client
* add HTTP PATCH tests to check high level response logic
* add permission-based 'kv patch' tests in prep to add HTTP PATCH
* adding more 'kv patch' CLI command tests
* fix TestHandler_Patch_NotFound
* Fix TestKvPatchCommand_StdinValue
* add audit log test for HTTP PATCH
* patch CLI changes
* add patch CLI tests
* change JSONMergePatch func to accept a ctx
* fix TestKVPatchCommand_RWMethodNotExists and TestKVPatchCommand_RWMethodSucceeds to specify -method flag
* go fmt
* add a test to verify patching works by default with the root token
* add changelog entry
* get vault-plugin-secrets-kv@add-patch-support
* PR feedback
* reorder some imports; go fmt
* add doc comment for HandlePatchOperation
* add json-patch@v5.5.0 to go.mod
* remove unnecessary cancelFunc for WriteBytes
* remove default for -method
* use stable version of json-patch; go mod tidy
* more PR feedback
* temp go get vault-plugin-secrets-kv@master until official release
Co-authored-by: Josh Black <raskchanky@users.noreply.github.com>