fix(ios): use weak instead of assign in properties for Objects

[vijaysingh-axway]

https://jira.appcelerator.org/browse/TIMOB-28413
https://jira.appcelerator.org/browse/TIMOB-28344
In general 'assign' is used for primitive data types and 'weak' is used for objects. If object is deallocated from anywhere, any 'weak' reference to that object is set nil. In assign, if object is deallocated you will still have a pointer to it's memory (which is garbage now)

[build]

	Fails
🚫	Tests have failed, see below for more information.

	Messages
📖	✊ The commits in this PR match our conventions! Feel free to Rebase and Merge this PR when ready.
📖	❌ 2 tests have failed There are 2 tests failing and 961 skipped out of 16041 total tests.
📖	💾 Here's the generated SDK zipfile.
📖	👍 Hey!, You deleted more code than you added. That's awesome!

Tests:

Classname	Name	Time	Error
ios.ipad.Titanium.UI.TableView	All text should show if TableView.style is .INSET_GROUPED (14.4.0)	0.497	Error: expected 'Ti.UI.View' to match image ('snapshots/tableview_style_inset_grouped@2x.png') mismatched pixels. allowed: 14840, actual: 53921 value@file:///node_modules/should/cjs/should.js:356:23 file:///ti.ui.tableview.test.js:1811:28 run@file:///ti.main.js:8796:22 processImmediateQueue@file:///ti.main.js:8859:18 drainQueues@file:///ti.main.js:8836:52
ios.iphone.Titanium.UI.TableView	All text should show if TableView.style is .INSET_GROUPED (14.4.0)	0.869	Error: expected 'Ti.UI.View' to match image ('snapshots/tableview_style_inset_grouped@3x.png') mismatched pixels. allowed: 14840, actual: 200203 value@file:///node_modules/should/cjs/should.js:356:23 file:///ti.ui.tableview.test.js:1811:28 run@file:///ti.main.js:8796:22 processImmediateQueue@file:///ti.main.js:8859:18 drainQueues@file:///ti.main.js:8836:52

Generated by 🚫 dangerJS against 263732e

[sgtcoolguy]

Could this be the cause of https://jira.appcelerator.org/browse/TIMOB-28296 ? There we have pretty consistent crashes with Ti.UI.Picker on macOS for dates - where some underlying object is GC'd and we're trying to send it messages.
mocha_2021-04-09-082446_macos-walle.crash.txt

Do we need to make the TiUIPicker's UIControl *picker field weak?

[vijaysingh-axway]

Could this be the cause of https://jira.appcelerator.org/browse/TIMOB-28296 ? There we have pretty consistent crashes with Ti.UI.Picker on macOS for dates - where some underlying object is GC'd and we're trying to send it messages.
mocha_2021-04-09-082446_macos-walle.crash.txt

Do we need to make the TiUIPicker's UIControl *picker field weak?

It doesn't look we have to make UIControl *picker field weak . I'll look in this crash.