fix: pass context to all http requests in microcks and keycloak clients

[mugiwaraluffy56]

all http requests in MicrocksClient and KeycloakClient were built with http.NewRequest, which doesn't accept a context. this means there's no way to cancel an in-flight request from the caller side — if a call hangs, it just hangs.

switched everything over to http.NewRequestWithContext and added context.Context as the first parameter to all interface methods that make http calls. callers in cmd/ pass context.Background() for now, which keeps behaviour identical while making it possible to wire up proper timeouts later (e.g. in the polling loop in cmd/test.go).

files changed:

• pkg/connectors/microcks_client.go — updated MicrocksClient interface and all five method implementations
• pkg/connectors/keycloak_client.go — updated KeycloakClient interface and all three method implementations
• pkg/watcher/executor.go — updated UploadArtifact call
• cmd/importDir.go — updated local MicrocksClient interface and ImportDirectory signature
• cmd/importDir_test.go — updated mock and test calls to match
• cmd/import.go, cmd/importURL.go, cmd/test.go — pass context.Background() at call sites
• cmd/login.go — threads cmd.Context() through to all keycloak and microcks calls

note: this is a breaking change to the MicrocksClient and KeycloakClient interface signatures. any code outside this repo that implements or calls these interfaces will need to be updated.