chore: show topup/increase option ony if available

[bumi]

The backends without channel management do not have support for this.

• could those boxes be reusable components?
• could the channel pages check if channel management is available and if not redirect to home?

[rolznz]

could those boxes be reusable components?

I don't think the design is finalized yet, so it might be best to wait for that

could the channel pages check if channel management is available and if not redirect to home?

We could do this, but there should be no way to access those pages normally (as long as we don't forget to implement these checks :sweat_smile: )