Add autoComplete widget and add to TypedInput for msg. props

[knolleary]

• New feature (non-breaking change which adds functionality)

This adds a new autoComplete widget that can be applied to any <input type="text"> that gives an auto-complete dropdown whilst typing in the input.

This is applies that to the msg. type of the TypedInput, with a (for now) hardcoded list of all message properties that core nodes use.

Even with the hardcoded list, this is already really useful.

But I plan to follow up with a design proposal for how nodes can provide a list of the properties they care about - distinguishing those they receive vs those they send. It would then be feasible for contrib nodes to add to the auto-complete list and it would also be able to sort the suggested completions based on whether a given type exists in the upstream or downstream flow. In that scenario, it would still show valid completions across the whole set as the node may not yet be wired.... and the user is free to ignore the suggestions and type whatever they want.

It would also be feasible to add similar completion to the flow and global types - but that's for another day.

[coveralls]

Coverage increased (+0.03%) to 67.723% when pulling e2d7fcb on auto-complete into 57386ed on dev.