Add missed z_view_keyexpr_* methods

[sashacmc]

Describe the release item

• z_view_keyexpr_from_str_autocanonize include/zenoh_commons.h#L3541
• z_view_keyexpr_from_substr include/zenoh_commons.h#L3567
• z_view_keyexpr_from_substr_autocanonize include/zenoh_commons.h#L3581
• z_view_keyexpr_from_substr_unchecked include/zenoh_commons.h#L3596

[sashacmc]

z_view_keyexpr_from_str_autocanonize - done: https://github.com/eclipse-zenoh/zenoh-pico/pull/487

z_view_keyexpr_from_substr* - can't be done without significant rework, currently keyexpr _suffix stored as pointer to null terminated string, to allow creating view_keyexpr from substr it should be changed to store _z_string_t.

[jean-roland]

@milyin could you please assign it to me?