improve debugging possibilities of error messages

[lifeart]

If passed fn for did-insert is not an function, it's literally udebuggable across application (there is no mentions of key name, component name, closest dom node and such)

[gnclmorais]

I’d be happy to have a go at this. I’ve been bitten by it before… 😅

[NullVoxPopuli]

Maybe the error could read:

<div
    {{did-insert undefined}}
                 ^ Expected value to be a function, instead received "undefined"


This error occurred in: "path/to/file" on line #, column #.
And was encountered while rendering:
  <ComponentA>
    <ComponentB>
        <ThisComponnent> <- this component

?

I think there are apis for getting the component stack? I forget what they are though? maybe @rwjblue remembers ;)