[improvement] make clear if a thread needs input or is ready for implementation

[cglantschnig]

When you create a thread in plan mode and you leave it, you don't see it's current state.

Currently you can follow the following states

• PR open
• PR merged
• working

I think it would be a great addition to have 2 states that are relevant for thread in planning mode

• waiting for input (happens when it ask you for further clarification to your plan)
• ready for implementation (when the plan is ready and you click on the implementation button)

just add some label, similar to working in the UI

[MatejSkarka]

This would help a lot

[maria-rcks]

#701