Support wildcard and regex column patterns for table formatting

[mattrunyon]

We should support wildcards and regex in table formatting. For example, *_percent could be used to format any column ending in _percent as a percentage.

A few things we need to determine:

1. How to distinguish wildcard vs regex. I propose /regex/flag and detecting if there are forward slashes to indicate regex. Since forward slashes are not valid column name characters, I think this should be fine. Ensure underscores are fine without escaping or make a note if they need to be escaped.

2. Should there be case sensitivity for either wildcard or regex? For regex if we support flags then we can do case sensitive by default (really the only flag we should probably support is insensitive since global can cause issues with re-using the regex and I think most/all other flags wouldn't matter for column names).

   For wildcards, case sensitivity probably makes sense. Although the comparison would be quick filters which we make always insensitive and only support trailing wildcards.

[mofojed]

Could use Python r-strings to support this.