[TOOL-2999] SDK: automatically sign message for SIWE in connect UI fo…

…r Ecosystem wallets (#5914)

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title: "[SDK/Dashboard/Portal] Feature/Fix: Concise title for the changes"
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## Notes for the reviewer
Anything important to call out? Be sure to also clarify these in your comments.

## How to test
Unit tests, playground, etc.

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## PR-Codex overview
This PR focuses on improving the `SignatureScreen` component by updating the signing flow for different wallet types and enhancing the user experience by removing unnecessary prompts for signing messages.

### Detailed summary
- Added `isHeadlessSignSupported` function to determine wallet support.
- Updated `SignatureScreen` logic to handle headless signing for supported wallets.
- Refactored tests to improve clarity and organization.
- Enhanced error handling and loading states in the UI.
- Introduced mocks for `useActiveWallet` and `useAdminWallet` in tests.

> ✨ Ask PR-Codex anything about this PR by commenting with `/codex {your question}`

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.changeset/six-snails-reflect.md

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+"thirdweb": patch
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+Do not prompt user for signing message for SIWE auth in Connect UI for Ecosystem wallets