UI: Add support for hiding columns.

[vanlooverenkoen]

Sometimes you only want to view some columns. It would be nice to have an option to hide/show certain columns.

Maintain this option when switching between tables

[NicolaVerbeeck]

There are some options we have here:

1. In custom queries show only returned columns
2. Option to hide columns, but clashes with option 1

[vanlooverenkoen]

Or both?

When using a custom query ignore the hide column option.