add zapstore to "Add a new application" screen

[alltheseas]

benefit: ZS button/link leads to a selection & discovery of nostr applications on Zapstore -> increased use of amber

mockup

[greenart7c3]

I can add it but there's only a few native apps that supports bunker login. This screen is bunker only, native apps that support amber don't need to add the app manually
I show this screen when you first start create/login to your account: