Create a menu for test case selection

[martinmladenov]

Description

Create a menu in the tool window which can be used by other components of the plugin (generating tests for a class, generating tests for a method, etc.) to allow the user to view the generated tests.

Definition of Done

• In the TestGenie tool window, there is a tab to show generated tests
• There is a way for other plugin components to use this tab programmatically
• Each generated test case is showed in a small read-only editor within the tool window (stacked vertically on top of each other)
• Next to each test case, there is a checkbox to select or deselect the test (selected by default)
• There is an "Apply" button to apply the selected test cases (no need for actual functionality just yet)

[martinmladenov]

I envision something similar GitHub Copilot's UI, with small read-only editors that display the generated test cases, and a checkbox next to each test case in order to select or deselect it.