lang: Allow custom lifetime for Accounts structure

[Aursen]

Problem

Currently, we can't write a syntax like this:

#[derive(Accounts)]
pub struct CustomLifetime<'a> {
    pub non_generic: UncheckedAccount<'a>,
}

Summary of changes

• Use trait_generics in to_account_infos macro generation.
• Use trait_generics in try_accounts macro generation.

[vercel]

@Aursen is attempting to deploy a commit to the coral-xyz Team on Vercel.

A member of the Team first needs to authorize it.

[acheroncrypto]

Awesome, thanks!