Task.add annotation label for link

[SergeyPirogov]

Changes:
This PR corresponds to isssue #353 and add support for Link annotation labling.

Example:
I have test marked by Custom annotation Jira("Jira-456"), so I want to make Allure recognize it as Link and Story:

Before:

@Test
@Story("JIra-1")
@Link("Jira-1")
public void dummyTest(){}

After:

@LableAnnotation(name = "story")
@LableAnnotation(name = "link")
public @interface Jira {}

@Test
@Jira("JIra-1")
public void dummyTest(){}

Checklist

• Sign Allure CLA
• Provide unit tests

[baev]

Thanks for the pull request. I so happy that you like our new @LabelAnnotation feature. But could you please explain in more details what is the use-case of such behaviour for links? I'm ok with adding such functionality but I think we should design it more carefully at this point

[SergeyPirogov]

@baev Please provide your feedback after comments fix

[baev]

@SergeyPirogov thanks!