This change aims to eliminate the dependency on `ctx_shell` in
the Bluetooth `mesh/shell/*`, making the code more maintainable.
Replaced `shell_*` functions that depended on `ctx_shell` with
the appropriate `bt_shell_*` functions.
Signed-off-by: Pisit Sawangvonganan <pisit@ndrsolution.com>
Moves around the shell files so that they are placed nearer
to the features they expose access to.
A few changes as possible has been made.
Signed-off-by: Emil Gydesen <emil.gydesen@nordicsemi.no>