Most Tables Lack Programatically-associated Headers

[BlindGuyNW]

In general, many tables in MekHQ are not very accessible for screen reader users. THe table headers are not programatically associated witht heir columns, and this makes navigating tables quite confusing.

For instance, the Briefing ROom tables have headers which are labels outside of the tables themselves, such as "Scenario," "date," and "Resolution," but these are not associated in any way with the contents of the table cells. A similar problem is present on the Personnel tab, and in general throughout the program where tables are used.