Circleguard

* visualizer now lets properly you view all negative time frames, and starts at the lowest negative frame instead of 0
* display distance to nearest hitobj in the visualizer
* increase default window size slightly so two loadables can fit side by side
* don't show scary JSONDecodeErrors errors when no error has actually occurred
* fix snaps rarely being counted off hitobjs even when "ignore snaps not on hitobjs" was checked
* hopefully fix circleguard not running on apple silicon macs by upgrading from PyQt5 5.14.2 to 5.15.2

* add option to ignore snaps that don't occur on hitobjects (enabled by default)
* replays played with HR are now shown correctly (ie flipped) when visualizing. If multiple replays are visualized and only one has HR, all replays are still flipped
* don't create a new loadable when "Select a Loadable" is re-selected
* display a nicer error message when non-std replays are investigated
* use cleaner links to maps and replays in templates

* fix local replays not thinking it was filled if you selected the default folder
* don't require disabled loadables to be filled
* fix some beatmaps not parsing correctly (https://github.com/llllllllll/slider/issues/71)
* fix `circleguard://` url erroring if log level was set to TRACE
* fix problematic replays potentially being removed twice and erroring

* **fix a memory leak** that occurred when deleting loaded loadables
* **ability to selectively disable loadables** (signified by a blue check or red X). Additionally:
- shift+clicking the blue check will disable all loadables other than the one you clicked
- shift+clicking the red X of any disabled loadable will re-enable all loadables
* put most recent runs at the top of the Queue tab instead of the bottom
* rewrite introduction page that shows to new users

* new Investigations screen which doesn't require drag and drop
* add hotkeys for creating loadables:
* <kbd>R</kbd> - creates a Map Replay
* <kbd>L</kbd> - creates a Local Replay
* <kbd>M</kbd> - creates a Map
* <kbd>U</kbd> - creates a User
* <kbd>A</kbd> - creates a All User Replays on Map
* show a pointer cursor on hover of clickable widgets
* save window size and position across restarts
* add mods of each replay to `circleguard://` urls
* display frametime difference in replay data
* skip ur calc for replays on maps with bugged downloads
* update threshold tab separator names
* prevent scrolling from activating dropdowns
make "Copy Template" button slightly bigger

* fix ur being wrong for maps / users with mixed mod combinations on the leaderboard
* allow multiple cg instances to coexist (with some caveats involving circleguard:// urls)
* fix beatmaps with catmull sliders crashing
* better and shorter error messages for common errors
* replace non-working windows shortcut with vbs script
* add message when a replay could not be found
* skip replays with no data (not in top 1k of beatmap) after load
* replace api key with asterisks in logs
* fix "inf" threshold value not actually corresponding to an infinite threshold
* make some labels selectable / copyable