tmgmt webform options translation is broken with option values containing spaces or dots

Problem/Motivation

https://php.net/manual/language.variables.external.php notes

Dots and spaces in variable names are converted to underscores. For example <input name="a.b" /> becomes $_REQUEST["a_b"].

Webform option names can contain spaces and dots, indeed WebformOptions::convertValuesToOptions defaults to $option_value = $option_text; if the value is empty. Since there it is a value and not a key, this causes no problems for webforms.

Proposed resolution

# is already converted to pound_ so just extend it to also convert dots and spaces.

Remaining tasks

Write a test?

Note I attached a little testing script which I found mighty useful while figuring out what's going.

User interface changes

API changes

Data model changes

Release notes snippet