pbx.c: expand fields width of "core show hints"

pbx.c: expand fields width of "core show hints"

The current width for "extension" is 20 and "device state id" is 20, which is too small.
The "extension" field contains "ext"@"context", so 20 characters is not enough.
The "device state id" field, for example for Queue pause state contains Queue:"queue_name"_pause_PSJIP/"endpoint", so the 20 characters is not enough.

Increase the width of "extension" field to 30 characters and the width of the "device state id" field to 60 characters.

Resolves: #770

UserNote: The fields width of "core show hints" were increased.
The width of "extension" field to 30 characters and
the width of the "device state id" field to 60 characters.