Provide a way to replace part of (or all) icons used by components with icons from other icon sets

[ChronosSF]

Is your feature request related to a problem? Please describe.

There is no simple way to have a sweeping replace of icons if apps' styling guidelines require the usage of an icon library that is not Material. Templating can be cumbersome solution and not all icons are exposed as part of templates anyway.

Describe the solution you'd like

The implementation could be something like an option with a mapping between icon names we use and what should be displayed (say a list of css classes) for igx-icons for these names. TBD

Describe alternatives you've considered

Alternatively every single icon should be templatable though that makes a full replace more difficult.