History popup slows down text input

[chrisduerr]

When the history popup opens, there's a clear delay in text repetition. Might be worth investigating if the performance can be improved here, since the popup should ideally be fully asynchronous.

Things that need fixing:

• [X] OptionMenu::scroll
• [x] OptionMenu::draw

[chrisduerr]

Some slow related functions:

Function	Mean
Overlay::draw	58.594 ms
Ui::draw	4.783 ms
Window::open_history_menu	28.397 ms
History::matches	1.650 ms

[chrisduerr]

Further drilldown into Overlay::draw indicates the amount of text rasterization for each individual item is at fault:

Possible solutions:

• Do NOT render items that aren't visible
• Move that logic into separate thread
• Parallelize rasterization of individual entries

[chrisduerr]

Further drilldown into Window::open_history_menu indicates the height calculation for each individual layout is at fault:

Possible solutions:

• Avoid calling layout.pixel_size, instead get line height from metrics once for each font and use that as height
• Move that logic into separate thread
• Parallelize rasterization of individual entries