Propose a transaction creation link

[rzadp]

• When prompted, we respond with a TX creation link - example new example
• Removed restriction to allowed github team - because the bot doesn't send any transactions to the blockchain or doesn't edit anything - we only respond back with a link.
• Compared the created proposal remark with 3 different on-chain referenda, and all seems good:
  • this fork with that
  • this fork with that
  • this fork with that
  • (note that some of them have incorrect APPROVE_RFC instead of RFC_APPROVE, but the rest matches)

The part with transaction hex creation is quite crazy.
We create a Kusama transaction, and then monkey-patch it to be a Polkadot-Collectives transaction.
PRs to make it more sane are welcome - I spent quite some time on it and this is the best I could come up with. 😅

[rzadp]

@mordamax @Bullrich I made updates and responded to your reviews.

[mordamax]

🚀