Support subtest case in go-test profile

[Konboi]

What

In Go, we can define subtests like the example below.
However, in the test report, they are shown as a single test case using the format: test function name / subtest name.
But when using the go test -list command, which is used for subsetting, only the test function names are output—subtest names are not included.
So we need to update the Go test profile to support subtests.

e.g) subtest example

t.Run(tt.title, func(t *testing.T) {...}

go test -llist result

go test -list="Test|Example" ./...
TestExample1
TestExample2
TestExample3
TestExample4
TestExample5
ok      github.com/launchableinc/examples/go    0.287s
TestGreeting
ExampleGreeting
ok      github.com/launchableinc/examples/go/example    0.475s

report example

        <testcase name="TestExample5/Test_case_2_(fail_case)" classname="github.com/launchableinc/examples/go" time="0.000">
            <failure message="Failed"><![CDATA[    example3_test.go:38: expected 8, got 7]]></failure>
        </testcase>

Created data used by this PR: cloudbees-oss/smart-tests-integration-examples#89

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[Konboi]

@ninjinkun or @ono-max Could you approve it? You don't have to review carefully