Linkify MMI codes

- Transforms MMI codes (as defined in 3GPP TS 22.030) into tel: URL.
- Skips MMI codes not terminating with the SEND function as they are
only processed "on-the-fly" while typing.
- Activated together with phone numbers matching.

Change-Id: I7ee7d3667b40afd6a97ee6115842be18b49f49a1
Signed-off-by: Pierre Crépieux <pierre.crepieux@orange.com>