History/slow chart view follow up

This is all the remnants and oustandings from #395 that we didn't clear up and/or discovered which need either fixes, further discussion

[ ] order markers on the slow chart seem to always stay in view despite the y-range when they should hide when out of view
[ ] open and closing the search bar (now adjacent to the slow chart) causes the pp nav in the slow chart to have line, arrow and labels extended to where the y-axis was moved to until one updates the view with an interaction
- this needs the same treatment as the Nav updates inside GodWidget.load_symbol()

[ ] should orders staged in one or the other chart be real-time mirrored in the other; iow as you move a line it moves proportionally in sync in the other chart?
- see draft commented code started inside OrderMode.stage_order()
[ ] should the linear range (aka the god view in the slow chart) set by the fast chart resize the view boundaries of the slow chart? As an example when you zoom out so much in the fast chart should the slow chart scale proportionally?
- also see example commented draft code in the callback def
[ ] on the slow chart, should we place an inf line from the last y-sticky to make it easy to y-align the current price with history?

[ ] right now the slow chart last value is updated at the same rate as the fast chart, is this excessive? Should we throttle it? right now it seems to be not much of a perf hit latency wise?

[ ] should the slow chart always keep the linear region's y-axis side at least 2 cursor widths (or wtv) offset from that axis to make it easy to get non-linear-region scrolling interaction without zooming out?
- likely this could be part of the .default_view() call triggered by the r hotkey?
[ ] right-click context menu support for loading fast chart data from a slow chart selection-region.
- almost got there in #401 😂
[ ] global view g hotkey triggered x-range sizing controls?
- g sizes current chart to it's "view all" datum set
- gg sizes all charts to all data (kinda like vim's go to the beginning of file hotkey?)
[ ] label with datums metrics always shown on interactions such that summary metrics are shown in slow chart (or some other lable or the window title bar?)
- eg. number of datums in view, amount of time that maps to
- updated on interactions such as zoom, pan?
[ ] modal level-triggered hotkey that when pressed makes the hist chart bigger?

pikers / piker