Add consistent error messages to ckm_db_tool

Add consistent error messages to ckm_db_tool

ckm_db_tool is a set of CLI utilities for debugging key-manager. Various
displayed error messages are inconsistent, do not display all available
information, and contain minor gramatical errors. Also, new interactive
features are planned to be introduced, which will require reading and
writing more information to the terminal.

A simple helper functions has been created for displaying error, warning
and info messages. All error messages have been changed to use them,
received grammar fixes, started displaying APICodeToString result when
possible, and rewritten to follow a consistent style. Finally, warning
and askPassword functions were implemented to prepare for next patches.

Change-Id: Ifd0608637f3f4ef3ce31c2fe7c79074da9a93bbb