[FEATURE] Button to create new Dodona exercise

[BTWS2]

Button (➕) in the upper right corner next to the blue checkmark to create a new Dodona exercise.
Before:

After:

Why would I like to see this feature added?

1. The VS Code extension only requires one click to create a new exercise. There are about 100 exercises in the course during the semester, so the button would be a nice addition. Compared to the VS Code extension, creating a new Dodona exercise in PyCharm requires several steps/clicks, which aren't that intuitive for young students:

• Right mouse button on folder (or File)
• New
• Dodona exercise

2. Students have to follow a manual and install everything before the first lab session. If they want to enter their API token, they have to create an exercise. Having the "create new Dodona exercise button" would allow for entering the API token, without following the steps mentioned in 1. The blue checkmark is grayed out, until there is a file opened.
   

3. Having a "create new Dodona exercise button" would allow the Project Panel to be collapsed and free up space to have the exercise description next to the code, just like the VS Code extension.
   Before:
   
   After: