[Arbitrary Txs] Add arbitrary transaction action form

[jakubcolony]

Figma designs: https://www.figma.com/design/5V8pr7iMwXsT9L3VAZsmUt/Actions-%26-Motions?node-id=24968-204505&node-type=frame&t=VK5oE9wW19JFFa0k-0
Feature spec: https://www.notion.so/colony/Arbitrary-Transactions-ba4b096b3b664cb09ef65ad35c4331fa

Description

Add Arbitrary transaction action type to the action form alongside all the required fields and the Contract interaction modal that shows on form submission.

Note: This is UI only, it doesn't need to be wired to any sagas at this point.

Acceptance criteria

• Both desktop and mobile views adhere to Figma designs
• It is possible to select any of the available decision methods (permissions, reputation and multi-sig)
• Contract interaction modal opens on Add transaction click
• There is the standard validation for common fields (title, decision method, description)

[rdig]

I'm deprioritizing this for the current cycle as we have a lot of QA issues to deal with and getting those deployed is highest priority right now.

We'll revisit this in the next cycle.