DLT-META demos: cannot use hypens in catalog name paramete

[lammic]

If you want to run demos against a catalog with a hyphen in its name, e.g,. dlt-test, the pipeline executions fail with:

ParseException: 
[INVALID_IDENTIFIER] The unquoted identifier dlt-meta is invalid and must be back quoted as: `dlt-meta`.
Unquoted identifiers can only contain ASCII letters ('a' - 'z', 'A' - 'Z'), digits ('0' - '9'), and underbar ('_').
Unquoted identifiers must also not start with a digit.
Different data sources and meta stores may impose additional restrictions on valid identifiers. SQLSTATE: 42602 (line 1, pos 3)

How to reproduce:

• create a catalog dlt-test
• run one of the demos in https://github.com/databrickslabs/dlt-meta/tree/main/demo
• the demo scripts check for the existence of dlt-test and pass the check
• pipeline executions fail becaus of unquoted catalog name

A straightforward solution is to disallow (for the demos) catalog names beginning with digits or containing hyphens. Preparing a PR for that.