toSide/toText properties are missing in data parameter of dependencyValidationStart event

[pmiklashevych]

https://www.bryntum.com/forum/viewtopic.php?f=44&t=14226

As a workaround user can take it from target/targetTerminal:

const scheduler = new Scheduler({
    listeners : {
        dependencyValidationStart({ data }) {
            console.log(data.toSide, data.toText); // empty string
            console.log(data.target.name, data.targetTerminal.dataset.side);
        }
    },

toSide/toText are set too late, see Scheduler/lib/Scheduler/feature/mixin/DependencyCreation.js

            getHtml        : ({ tip, event }) => {
                if (me.creationData) {
// onOverTargetTerminal fires 'dependencyValidationStart'
                    event && me.onOverTargetTerminal(event);
// generateTooltipContent adds toSide/toText info
                    return me.generateTooltipContent(tip, me.creationData);
                }
            },

Also maybe need to describe details of 'data' in https://www.bryntum.com/docs/scheduler/#Scheduler/feature/mixin/DependencyCreation#event-dependencyValidationStart

And maybe add toSide/toText to the
https://www.bryntum.com/docs/scheduler/#Scheduler/data/DependencyStore#function-isValidDependencyToCreate