feat(iOS, SplitView): Add API for organizing columns

[t0maboro]

Description

Closes https://github.com/software-mansion/react-native-screens-labs/issues/229

In this PR, I'm adding new APIs for SplitView column management. I updated SplitViewScreen component export to separate Column which is rendered as typical SplitViewColumn and Inspector which in some cases might be rendered as modal. Additionally, I'm adding a prop to Host for toggling inspector, at the moment it's really laggy, but I'm leaving it as a followup.

In this PR we also noticed that the logic for updating props needs to be updated. For number of columns management we need to delay SplitViewHostController initialization until we'll receive reactSubviews from the initial render. This is causing a problem, when 1st updateProps call is coming, because if inspector should be displayed, we need to notify the component about that fact. Therefore, this logic was rewritten to collect all prop updates in batch, create controller on 1st updateProps call and notify controller to flush updates on didMount.

Changes

• Updated SplitViewBaseApp
• Changed the logic for props updates
• Added showInspector prop to host component
• Added columnType prop to screen component
• Added assertions for unexpected column manipulations
• Updated JS definitions

Test code and steps to reproduce

Updated SplitViewBaseApp

inspector-mobile.mov

inspector-tablet.mov

Checklist

• Included code example that can be used to test this change
• Ensured that CI passes

[kkafar]

I have a series of remarks. This looks good overall.

[kkafar]

Last few remarks, and we shoudl be good!

[kkafar]

Include verbally agreed adjustments & let's go. Thank you!