Generic CIP22 support - desktop

[ohager]

Is your feature request related to a problem? Please describe.
Atm, we support the pay action as of CIP22. It would be useful to have a more generic approach, allowing generic signing of additional actions like:

• Token Transfer
• Message Sending(e.g. pool configuration, smart contract method calls, etc)
• Smart Contract creation

Describe the solution you'd like
Having a generic dialog showing the decoded payload and let's the user sign

• Define actions and payload models for the transactions
• Create a page to visualize all the information
• Document the spec like in https://github.com/signum-network/phoenix/blob/main/DEEPLINKING.md