Breaking changes: replaced usize with u32 for indices/u64 for file sizes, OAuth2Token::scopes returns string instead of iterator

[ldesgoui]

Plus some linting and explicit handling of num casting:

• SDK returning negative indices will panic, passing indices larger than i32 will panic
• Buffers larger than u32::max_value() bytes will only be written up to u32::max_value()

Some Error variants were renamed to shush clippy