Confusion around createNode( tandem ) and tandemName

[zepumph]

From https://github.com/phetsims/sun/issues/821, is a weird discrepancy going on with GroupItemOptions depending on how the items-based class implements things.

Work for this issue:

• Add lots of documentation about what createNode's tandem parameter is and tandemName. Most often tandemName is given to the parent of the node created by createNode.
• There is not a consistent pattern about what kind of tandem is passed to tandemName, for GroupItemOptions it is most often the parent tandem, and not the child for the node. That is confusing!
• Beyond just understanding how it is working now, let's make it consistent across all implementations!

I wasn't in the initial GroupItemOptions work, so I'm implicating someone that was (thanks @samreid)

[zepumph]

From https://github.com/phetsims/sun/issues/797#issuecomment-1382565726:

Removing unused tandem parameters made me realize that there is a bit of weirdness about how createNode provided a tandem. In many cases, the tandemName is used by a container of the createNode Node, and shouldn't be used. For example in https://github.com/phetsims/calculus-grapher/blob/b4483f1d83e27508b50bec00cf802d759a31019f/js/common/view/PredictModeRadioButtonGroup.ts#L55-L56. This makes things weird! Let's talk more.

[samreid]

Tagging for https://github.com/phetsims/phet-io/issues/1914 and self-unassigning.