Light-client: Align button style in dApp

[christianbrb]

Description

Currently, different button styles are used in the dApp. They should get aligned.

## Acceptance criteria
-

Tasks

• [ ]

[nephix]

Current buttons:

Action button (primary)

• Sticky:
  

• Not sticky, as well as ghost btn:
  

Secondary buttons

Menu buttons

[kelsos]

@nephix thank you.

Do we really need to do further alignment? From what I can see so far these buttons service different purposes.

[nephix]

Yes I agree. The only thing that I would change is making all secondary buttons (like Deposit on transfer screen) a ghost button, like Close on the channels screen