Identifiers (e.g., cube names) generated by the CLI and data model generating code might not be correct

**Describe the bug**
We have some tables in BQ in which the name is UUID. so it contains hyphen `-` and sometimes starts with a number. So the schema files generated by the cli will contain that as cube name.
Cube-server gives an error in parsing those schema files.

**To Reproduce**
Steps to reproduce the behavior:
1. Create a table with UUID or any string with a hyphen
2. Create schema with cli generate command
3. Start the cube server
4. It will throw the error in the terminal.

**Expected behavior**
It should sanitize the table name in cube name and in joins.
maybe replace the hyphens with underscores and add string prefix if the name does not start with an alphabet.