Execute tests from a relative path of a scenario file from the PWD(Present Working Directory)

Currently the Zerocode runner can execute a test from the Classpath. That's fine and we will retain this as this is given default to us.
See example:
https://github.com/authorjapps/zerocode/blob/master/http-testing-examples/src/test/java/org/jsmart/zerocode/testhelp/tests/helloworld/JustHelloWorldTest.java

```
@TargetEnv("github_host.properties")
@RunWith(ZeroCodeUnitRunner.class)
public class JustHelloWorldTest {

@Test
@Scenario("helloworld/hello_world_status_ok_assertions.json") <---------- picks from Classapth
public void testGet() throws Exception {
}

}
```

AC1:
===
But, we need a mechanism to make it flexible to run even if
- relative path is provided to the scenario file

Example 1:
```
$pwd
/home/authorj/code/zerocode
$

then, I should be able to run using below:
@Test
// should pick from relative-apth from PWD //
@Scenario("./http-testing-examples/src/test/resources/helloworld/hello_world_status_ok_assertions.json")
public void testGet() throws Exception {
}

// in the above PWD = /home/authorj/code/zerocode, which is represented by "."
```

Example 2:
```
$pwd
/home/authorj/code/zerocode/http-testing-examples/src
$

then, I should be able to run using below:
@Test
// should pick from relative-apth from PWD //
@Scenario("./test/resources/helloworld/hello_world_status_ok_assertions.json")
public void testGet() throws Exception {
}

// in the above PWD = /home/authorj/code/zerocode/http-testing-examples/src, which is represented by "."
```

-------
Linked Issue #722

AC = Acceptance Criteria

Start with the @Scenario usage in JustHelloWorldTest.java and the ZeroCodeUnitRunner entry point. Check the existing classpath-based scenario tests, then verify that paths beginning with ./ resolve from the process working directory while the current classpath behavior remains unchanged.

Written by the indexing model from the issue text.