Implement a common function to dissect IMSI and use it GSM MAP as a start.
- remove soft deprecated APIs and unused hf.

Change-Id: Id00c3dd35f3fc65f543bc29df6d35515c45fe7e1
Reviewed-on: https://code.wireshark.org/review/3715
Reviewed-by: Anders Broman <a.broman58@gmail.com>