Equals filter does not work for number column in the groupBy dev demo

[astaev]

Description

Equals filter does not work for number columns

• igniteui-angular version: 8.2.x
• browser: any

Steps to reproduce

1. Open the gridGroupBy DevDemo
2. Open Salary field's filters
3. Add a value(to default Equals condition) which equals to some of the cell values above

Result

Filter does not work at all
'Does not equal' also does not work

Expected result

Filtering should work as expected

Attachments

Attach a sample if available, and screenshots, if applicable.

[rkaraivanov]

@astaev
That's because the Salary column is explicitly marked as a number type, while in the underlying data, the salary prop types are strings. Basically the sample is configured in all manners of wrong