fix(test): return KindConnection error on polling timeout - #585

Description

• Hoisted inProgress variable out of the polling loop in cmd/testExecutor.go to track test state after the deadline expires.
• Returned errors.Wrapf(errors.KindConnection, ...) if inProgress is still true after the loop so the CLI exits with code 11 instead of 1.
• Skipped renderTestResult on timeouts so unfinished tests are not falsely reported as contract failures (FAILURE 0ms).
• Added unit test in cmd/testExecutor_test.go asserting errors.KindConnection and exit code 11.

Related issue(s)

Fixes #573

AI Disclosure

The code changes and unit test were written and verified by me. I fully understand them. I used an AI assistant to discuss the error-handling architecture.

Testing

• go build ./... : passes
• go test ./... : all packages pass
• go test -v -count=1 -run TestRunTestAndWait_TimeoutReturnsKindConnection ./cmd : passes (asserts exit code 11)
• Manual CLI test against hanging mock server: verified timeout error on stderr and exit code 11

$ ./microcks test "MyAPI:1.0" "http://localhost:8080" HTTP --microcksURL=http://127.0.0.1:8888 --waitFor=100milli
MicrocksClient got status for test "test-hanging-1" - success: false, inProgress: true 
MicrocksTester waiting for 2 seconds before checking again or exiting.
...
test polling timed out after 10100ms waiting for result test-hanging-1
$ echo $?
11