Move Shared<T> to types/mod.rs, bump some dependencies

[kozabrada123]

This pr includes various fixes:

• bump rustls to 0.21.11, to fix an (although n/a to chorus) security vulnerability
• bump h2 to 0.3.26 to fix another (although n/a to chorus) security vulnerability
• move type alias Shared<T> from src/gateway/mod.rs (feature locked behind client) to src/types/mod.rs, to fix compiler errors when building without the client feature:

  
  error[E0432]: unresolved import `crate::gateway`
  --> src/types/entities/mod.rs:30:12
  |
  30 | use crate::gateway::Shared;
  |            ^^^^^^^ could not find `gateway` in the crate root

error[E0432]: unresolved import crate::gateway --> src/types/entities/application.rs:10:12 | 10 | use crate::gateway::Shared; | ^^^^^^^ could not find gateway in the crate root

error[E0432]: unresolved import crate::gateway --> src/types/entities/audit_log.rs:7:12 | 7 | use crate::gateway::Shared; | ^^^^^^^ could not find gateway in the crate root ...

[kozabrada123]

Are you ok with moving Shared<T>? @bitfl0wer It seems like the easiest way to fix these import errors

[bitfl0wer]

Yes, this seems like a good idea :)