Breaking change in zenoh_macros::kedefine API

[fuzzypixelz]

Describe the bug

As of #752, the zenoh_macros::kedefine macro generates getters that return &zenoh_keyexpr::keyexpr for key expression format specs other than ** instead of returning Option<&zenoh_keyexpr::keyexpr> which was the behavior before the pull request in question was merged.

This is a breaking change for users of key expression format specs other than **, e.g. zenoh-plugin-ros1.

• Breaking change in zenoh_macros::kedefine API zenoh-plugin-ros2dds#88
• Breaking change in zenoh_macros::kedefine API zenoh-plugin-ros1#35

@p-avital

To reproduce

1. Sync zenoh-plugin-ros1's lockfile with Zenoh

System info

• Zenoh ref: 7d9d684

[fuzzypixelz]

Otherwise if this change is intentional, the documentation should be updated to reflect it:

Parsed will have a method named after each spec's id that returns Option<&keyexpr>. That Option will only be None if the spec's format was ** and matched a sequence of 0 chunks.

[p-avital]

I was unsatisfied with returning Options that would always be Some, so I opted for tanking the break. The generated docs for each individual method was updated, #783 updates the global docs :)