Warnings in PoC code

[yonas]

Describe the bug warning: using '.borrow()' on a double reference, which returns '&HashMap<Vec<u8>, Contact>' instead of borrowing the inner type --> cli/src/user.rs:333:40

To Reproduce Steps to reproduce the behavior:

1. git clone...
2. cargo build --release

Expected behavior No errors or warnings.

Actual behavior

$ cargo build release
...
warning: `openmls` (lib) generated 1 warning
   Compiling cli v0.1.0 (/git/openmls/cli)
warning: using `.borrow()` on a double reference, which returns `&HashMap<Vec<u8>, Contact>` instead of borrowing the inner type
   --> cli/src/user.rs:333:40
    |
333 |         for contact_id in self.contacts.borrow().keys() {
    |                                        ^^^^^^^^^
    |
    = note: `#[warn(suspicious_double_ref_op)]` on by default

Screenshots or debug log

Platform (please complete the following information):

• OS & OS version: FreeBSD 13.2
• x86_64
• Version: 837c7a9

[yonas]

Forgot to add this warning:

warning: private item shadows public glob re-export
  --> openmls/src/group/mod.rs:27:1
   |
27 | pub(crate) mod errors;
   | ^^^^^^^^^^^^^^^^^^^^^^
   |
note: the name `errors` in the type namespace is supposed to be publicly re-exported here
  --> openmls/src/group/mod.rs:37:9
   |
37 | pub use public_group::*;
   |         ^^^^^^^^^^^^^^^
note: but the private item here shadows it
  --> openmls/src/group/mod.rs:27:1
   |
27 | pub(crate) mod errors;
   | ^^^^^^^^^^^^^^^^^^^^^^
   = note: `#[warn(hidden_glob_reexports)]` on by default

[raphaelrobert]

Closed via #1611.