Feat: new app banner with redirect

[katspaugh]

What it solves

Shows a banner with our new URL and a redirect after a 10-second countdown.

[github-actions]

CLA Assistant Lite All Contributors have signed the CLA.

[coveralls]

Pull Request Test Coverage Report for Build 3384248745

• 0 of 24 (0.0%) changed or added relevant lines in 2 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-0.09%) to 41.836%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
src/components/PsaBanner/index.tsx	0	7	0.0%
src/components/PsaBanner/Countdown.tsx	0	17	0.0%

Files with Coverage Reduction	New Missed Lines	%
src/logic/safe/hooks/useOwnerSafes.ts	1	95.83%

Totals
Change from base Build 3321854842:	-0.09%
Covered Lines:	4777
Relevant Lines:	10425

---

💛 - Coveralls

[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	0	N/A

• Result: ✅ success
• Annotations: 0 total

---

^{Report generated by eslint-plus-action}

[francovenica]

Ok, had to check in my localhost to see the banner.
LGTM

The redirection works
The cancel button and close button (the "X") stop the redirect
The URL in the banner is fine
Once closed the banner doesn't show up anymore (expected)