Fix: EIP712 signing

[mmv08]

What it solves

This PR fixes bugs found in the EIP712 signing found by the 1inch team. They're the following:

• Unnecessary wrapping of the EIP712 typed data with Safe's EIP712 message structure
• Unnecessary JSON wraps/unwraps of the EIP712 data

How to test it

1. Run feat: Add Permissions and EIP-712 tests gnosis/safe-test-app#2
2. Use a test message, it should be a valid JSON. Example:

{"domain":{"verifyingContract":"0x0000000000000000000000000000000000000777","chainId":1},"message":{"message":"0x"},"types":{"SafeMessage":[{"type":"bytes","name":"message"}]}}

3. Paste it into the textarea
4. Click a button to sign it
5. Confirm that the message matches your test message
6. Sign and execute the signing
7. Check if the message is signed by clicking the button in the test app

Related SDK PR safe-global/safe-apps-sdk#361

[github-actions]

CLA Assistant Lite All Contributors have signed the CLA.

[github-actions]

ESLint Summary View Full Report

Annotations are provided inline on the Files Changed tab. You can also see all annotations that were generated on the annotations page.

Type	Occurrences	Fixable
Errors	0	0
Warnings	0	0
Ignored	1	N/A

• Result: ✅ success
• Annotations: 0 total

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^{Report generated by eslint-plus-action}

[coveralls]

Pull Request Test Coverage Report for Build 2970561889

• 6 of 9 (66.67%) changed or added relevant lines in 3 files are covered.
• No unchanged relevant lines lost coverage.
• Overall coverage decreased (-0.004%) to 42.105%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/routes/safe/components/Apps/hooks/useSignMessageModal.ts	1	2	50.0%
src/routes/safe/components/Apps/components/AppFrame.tsx	0	2	0.0%

Totals
Change from base Build 2963651285:	-0.004%
Covered Lines:	4776
Relevant Lines:	10360

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💛 - Coveralls

[github-actions]

Deployment links

⚪ Mainnet     🟣 Polygon     🟠 Rinkeby

[usame-algan]

Looks good 👍

[JagoFigueroa]

Todo bueno señores, gracias!