`TableView`: toggle selection filtering

Requires quite a bit of redesign but will also lay the groundwork for other related tasks.

[x] Generalise Redraw to support interactions other than Selector Val (see above)
- [x] Pull UIHelpers out of RendererSpec into Renderer
- [x] Use RendererSpec in signature of draw
- ~~Extra Drawable parameter to specify ViewSelector argument~~
- [x] Solve potential cyclic dependency/orphan instance problem (see above)
[x] Rethink (currently unused) ViewState in light of existentials
- [x] Move filter to TableView and update filterToggler accordingly
- [x] Implement a Setter Fig TableView to map filter toggler to view
- [x] unsafeUnpack to update under existential View
[ ] in_views and out_views never initialised
- [ ] Don’t actually need to persist the view part anyway – only the view state

Done/dropped:

[x] Add mouse handler to th element
[x] Parameterise TableView on whether to filter to selected rows only
[x] Button to toggle filtering on/off
~~#1011~~
[x] Include left/right selection information as part of view state
[x] Pass TableViewHelpers as separate argument to drawTableView
[x] mousedown handler on toggle button
[x] Pass filter toggle listener to TableView.js
[x] Call filter toggle listener in TableView.js and verify executing on PureScript side
[x] Experiment with View type class (more modular, potential to introduce per-view state type)
[x] Store view state inside View
[x] Supply view state as part of RendererSpec
[x] Remove filter from TableView
[x] Version of view which maintains state component and only updates view?

Current design:

Fig stores selections associated with inputs and outputs, plus whether mode is LinkedInputs or LinkedOutputs
Each view makes an EventListener mapping mouse event coordinates to selector for view
EventListener passed to JavaScript and attached to visual elements
When fired, listener turns mouse event coordinates into selector and passes to redraw of type Effect Unit
In drawFig, for each drawView, supply a redraw which re-runs drawFig with updated Fig state
unsafeUnpack to allow updating under existential View

Proposed design:

Redraw takes an Endo Fig rather than a Selector Val to an Effect Unit
selectInput/selectOutput step moves from drawFig into selListener
selectInput x/selectOutput generalises to type Endo View -> Endo Fig
Lift FilterToggler from Endo TableViewState to Endo View and thence to Endo Fig
Avoid potential cycle between App.View, App.View.Util (Drawable), and any App.View.[ViewType]
- App.View defines View, which has a constructor for every App.View.[ViewType]
- Every App.View.[ViewType] implements Drawable, which therefore can’t be in (or import) App.View
- Since MultiView and View are mutally defined, the former must be in App.View to avoid cycle (or orphan)

explorable-viz / fluid