Add only as an annotation for the describe/test

[OlehBabenkoo]

This feature adds support for the .only annotation in describe and test constructs. It allows running only the selected describe blocks or individual test cases, greatly simplifying the debugging and testing process by focusing on specific parts.

Key Changes:

1. Support for describe.only:

   • Added functionality to use describe.only to execute only a specific describe block.
   • All other describe blocks will be skipped.

   describe.only("This block will run", () => {
       test("Test in this block will also run", () => {
           expect(1).toBeEqual(1)
       })
   })

2. Support for test.only:

   • Added functionality to use test.only to execute a specific test within any describe block.
   • All other test cases in the same or other describe blocks will be skipped.

   describe("Test block", () => {
       test.only("This test will run", () => {
           expect(3).toBeGreaterThan(2)
       })
       test("This test will be skipped", () => {
           expect(true).toBeTruthy()
       })
   })