Improve mock services in unit tests

[ChinthakaJ98]

Description:

• [ ] When creating a mock service in the process of creating unit tests, after we give the required information and click on the mock service create button it is getting created but we are being directed back to the project overview page. But ideally we need to get redirected to the mock service selection page to continue with the unit test creation. This causes information loss as well because we were in the process of creating unit tests.

• [x] Also there is no option to edit an existing mock service via the UI of the extension.

[gigara]

@ChinthakaJ98 We can edit the mock service by double clicking the tree item.