Update samples to use repo analysis options, Fix sample templates and a ton of analyzer issues (#77868)

Add side property to Chips, and resolve it and the state of Chips to be MaterialState aware (#68596)

Adds MediaQuery.maybeOf to replace calling MediaQuery.of(context, nullOk: true), and removes the nullOk parameter. Also changes MediaQuery.of to return a non-nullable value, and removes many instances of the ! operator, reducing the possible places where a null dereference could occur.

* migrate material to nullsafety

* address review comments

* address review comments

* fix build

The remaining uses of this pattern were all due to wanting to have
the child's slot when `Element.forgetChild()` was called. However,
when that method is called, the child's `slot` value is still valid
in the context of the parent, so the uses can just use `child.slot`.

This is the final round of cleanup from the fallout of #63269

This reverts commit ce40de69.

(this re-applies #64189 by reverting #64249)

This reverts commit 21cfed34.

* (insert|move|remove)ChildRenderObject Deprecation: Step 1

This deprecates the following methods:

* RenderObjectElement.insertChildRenderObject
* RenderObjectElement.moveChildRenderObject
* RenderObjectElement.removeChildRenderObject

...and replaces them with the following methods:

* RenderObjectElement.insertRenderObjectChild
* RenderObjectElement.moveRenderObjectChild
* RenderObjectElement.removeRenderObjectChild

The reason for the deprecation is to provide the `oldSlot` argument to
the `moveRenderObjectChild` method (such an argument was missing from
the now-deprecated `moveChildRenderObject` method) and the `slot`
argument to the `removeRenderObjectChild` method (such an argument was
missing from the now-deprecated `removeChildRenderObject` method). While
no argument was added to `insertRenderObjectChild`, the name change (and
corresponding deprecation) was made to maintain naming parity with the
other two methods.

This initial step does not update or remove any of the `slotToChild`
patterns that exist in the framework. This work is being separated
into two commits in case something needs to be reverted to minimize
the scope of each commit.

See https://github.com/flutter/flutter/issues/63269 for more info

* Add punctuation for unterminated sentences in doc comments

* Addressing review nit

Updated references to the old button classes to the new ones in comments and documentation for classes in the material library. (#62092)