Add ability to use functions in scriptable properties

[calebmusson]

function parseFunctionString(
    value: string
): CallableFunction | undefined | string {
    if (
        typeof value === 'string' &&
        value &&
        (value.startsWith('function (') || value.startsWith('function('))
    ) {
        // eslint-disable-next-line prefer-const
        let fn: CallableFunction | undefined = undefined
        console.log(`function found: ${value}`)
        eval('fn = ' + value)
        return fn
    } else {
        console.log(`function not found: ${value}`)
        return value
    }
}

[benmusson]

Draft of function support added in b38b44cbe02a405ae159b97d4ca568ab1ed344c1. An alternative syntax return was used to search for scripts, for the following reasons:

1. eval is very unsafe (as opposed to new Function() which is just normal unsafe).
2. writing function (context, options){} takes up a lot of precious space in the property editor.

Currently all properties (including bound data) is scanned for scripts. Let's see what performance looks like, but I think we should at least black-list datasets[x].data from scanning.