Replace non-printable characters in cf-names so they may be seen by humans in artefacts

[udi-speedb]

CF names may contain any character. It so happens that there are users that choose non-printable characters when naming their cf-s. For example, I have seen a user whose cf-names were generated automatically as the numbers 1, 2, 3, ...
When converted to strings, the name of the cf is the characters whose ASCII value is 0x1, 0x2, 0x3, ...
These are non-printable ASCII characters and it causes issues when viewing the parser's artefacts.

The proposal is to find some mechanism to replace the non-printable characters with some printable character, while preserving the uniqueness of the names of the cf-s.