refactor: enhance TLS cert generation and refactor HTTP client architecture (#3638)

- Refactored HTTP client from global cache to struct-based approach (global state was shared between tests, including what certificates to use)
- Enhanced pkg/test/tls to support ECDSA and ED25519 key types
- Replaced static certificate files with dynamic generation in golang tests
- Fixed test cleanup issues and improved resource management

This eliminates dependency on external cert generation scripts and
improves test maintainability.

Signed-off-by: Andrei Aaron <andreifdaaron@gmail.com>

pkg/cli/client/server_info_cmd_test.go

@@ -112,15 +112,17 @@ func TestServerStatusCommandErrors(t *testing.T) {
 
 		// invalid URL
 		err = GetServerStatus(SearchConfig{
-			ServURL:      "a: ds",
-			ResultWriter: os.Stdout,
+			ServURL:       "a: ds",
+			ResultWriter:  os.Stdout,
+			SearchService: NewSearchService(),
 		})
 		So(err, ShouldNotBeNil)
 
 		// fail Get request
 		err = GetServerStatus(SearchConfig{
-			ServURL:      "http://127.0.0.1:8000",
-			ResultWriter: os.Stdout,
+			ServURL:       "http://127.0.0.1:8000",
+			ResultWriter:  os.Stdout,
+			SearchService: NewSearchService(),
 		})
 		So(err, ShouldBeNil)
 	})
@@ -129,7 +131,7 @@ func TestServerStatusCommandErrors(t *testing.T) {
 		port := test.GetFreePort()
 		result := bytes.NewBuffer([]byte{})
 		searchConfig := SearchConfig{
-			SearchService: mockService{},
+			SearchService: newMockService(),
 			ServURL:       fmt.Sprintf("http://127.0.0.1:%v", port),
 			User:          "",
 			OutputFormat:  "text",