Improving readability of errors

[joshua-hampton]

Started work on improving how errors are printed to display to aid understanding of errors from regex rules. For example, if a value is meant to (but does not) meet the regex rule "datetime", previously the error printed was

[global-attributes:******:time_coverage_start]*** Value '20230609' does not match regex rule: 'datetime'.

Now, an example of a valid value is also printed:

[global-attributes:******:time_coverage_start]*** Value '20230609' does not match regex rule: 'datetime' - Example valid value '2023-11-17T15:00:00'.

[joshua-hampton]

This is now ready to be merged. The above regex-rule examples have been filled out to all regex rules in rules.py-Rules-static_regex_rules, and additional quote marks have been added to some error messages around the values for easier reading and understanding, e.g.

Attribute 'long_name' must have definition Cloud Base Altitude (Geometric height above geoid WGS84), not Cloud Base Altitude (Geometric height above geoid (WGS84)).

would now print as

Attribute 'long_name' must have definition 'Cloud Base Altitude (Geometric height above geoid WGS84)', not 'Cloud Base Altitude (Geometric height above geoid (WGS84))'.

This will be particularly helpful when values end in punctuation, clarifying whether that punctuation is part of the value or the message.