MST: Add `symbol` delegate provider for tuples

[CommanderTvis]

Use case:

val (x, y) by symbol // symbol: ReadOnlyProperty<Any?, Pair<Symbol, Symbol>>

[CommanderTvis]

Not sure if it is possible

[altavir]

I think it is possible, but it does not make any sense. Saving lines on symbols seems useless.

[CommanderTvis]

It's beautiful

[altavir]

I see no valid use-case for it. So won't fix unless you give some reasoning beyond one line in the whole project economy.

[CommanderTvis]

It isn't possible