Issues with Grid Cascading Combos sample

[IGvaleries]

1. when run from online samples (https://www.infragistics.com/products/ignite-ui-web-components/web-components/components/grids/grid/cascading-combos) an error is thrown in the console
   Uncaught Error: Error on fetching sample files!
   at t.sampleFilesFetchErrorHandler (main.20558c30825c55ce5c13.js:1:32991)
   at Object.error (main.20558c30825c55ce5c13.js:1:32154)
   at fire (jquery-3.1.0.js:3243:31)
   at Object.fireWith [as rejectWith] (jquery-3.1.0.js:3373:7)
   at done (jquery-3.1.0.js:9100:14)
   at XMLHttpRequest. (jquery-3.1.0.js:9340:9)

2. when built from samples source (seen in vnext branch) and run, if you select an item from the first combo, when you try and select an item from the first combo an error is received:
   ResizeObserver loop completed with undelivered notifications.
   at handleError (http://localhost:8080/f8b58105e030fc6a931c.bundle.js:79533:58)
   at http://localhost:8080/f8b58105e030fc6a931c.bundle.js:79552:7

[MarielaTihova]

1. Resolved with the PR linked to this issue (Fixed cascading combos console error igniteui-xplat-docs#1436)
2. Happens only in dev mode