Sort table key listings in debug views

[infogulch]

When browsing large lists in the Variables, Watch, or variable hover views while debugging, it is frustrating to search for keys in big tables like data.raw and data.raw["items"]. It would be much easier if keys for these tables were sorted before they are displayed.

This could have the downside of sorting "struct" keys for prototypes (because there is no actual difference between "structs" and "dicts" in lua, everything is a table), which is obviously undesirable. A potential workaround is to sort a table's keys for display only if it doesn't have a "type" key, since all prototypes have a type and no big lists of prototypes have an element named "type".