fix: add copy button to some dropdown accounts

[NeOMakinG]

Description

There are a few places where we want to add the copy button to the dropdown accounts components:

• Send modal
• Defi Overview
• rFOX addresses

I also removed the account auto selection based on the highest amount account, because it was causing a bug inside AccountDropdown where this component didn't know the accountId changed, it was used as default value but not as a reactive value

As this logic is buggy and almost everyone agrees that we should ditch it, I removed it and the bug naturally disappeared

⚠️ We shouldn't show this for UTXOs accounts

Follow up of #7663 as AccountDropdown was a specific case

Issue (if applicable)

closes #7624

Risk

Low

High Risk PRs Require 2 approvals

What protocols, transaction types, wallets or contract interactions might be affected by this PR?

Testing

• Go to Send modal, select an asset and add an address, the account selected should be kopiable
• Go to any defi opportunity, in the overview view, the account selected should be kopiable
• Every rFOX AccountDropdown components should be kopiable
• For all those cases, in case the account is an UTXO, it should not be kopiable

Engineering

n/a

Operations

n/a

• 🏁 My feature is behind a flag and doesn't require operations testing (yet)

Screenshots (if applicable)

[gomesalexandre]

see inline comments

[gomesalexandre]

Tested locally:

• DeFi ✅

https://jam.dev/c/8b98c3aa-8a6e-4cc5-a684-120ba8d46b46

• Send input ✅

https://jam.dev/c/a34bf5b7-d7cb-4135-bfc0-45d160b1186f

• RFOX 🚫

Multi-account RUNE address isn't copied, the 0th account_index is instead

https://jam.dev/c/2fcd4ebf-b8c5-419e-aa78-fa57938f73d8

[gomesalexandre]

Retested locally, confirmed RFOX is now happy:

• RUNE Addy

https://jam.dev/c/ce329792-051d-4148-a80a-eabccf4fe242

• FOX.ETH / FOX.ARB addy:

https://jam.dev/c/a00d342f-e294-4823-9db4-5656e24aeb64