MonacoQueryInput styling tweaks

Created by: lguychard

Some UI polish on the Monaco query input. Screenshots in Details.

• Use the keyword color from our regular syntax highlighting themes to highlight filters, and the regular query input color for the rest of the text.
• Tweak suggestions widget colors to better match our light and dark themes.

• Fix off-by-1px height difference between the query input and surrounding UI elements.
• Match padding-left from the regular query input (previously had no padding).
• Cursor is thinner, and longer takes the full height of the input.

• Don't use absolute positioning for in-field toggles to avoids conflict with query text.

• Don't display a box shadow around Monaco's .inputarea element, fixes a small visual blip above the cursor position.