[grid-pro] Allow custom web components as editors

[probert94]

Describe your motivation

The GridPro currently only supports Text, Select and Checkbox fields as well as custom server-side components.
The disadvantage of the custom server-side components is, that the correct value is only shown after a roundtrip (see vaadin/web-components#2550).
As stated in a comment to this issue, probably the best way to support all custom editors would be to support custom webcomponents.
This would probably also solve the column type missing issues (vaadin/web-components#1037, vaadin/web-components#1052, vaadin/web-components#1104) as they should then be relatively simple to implement (vaadin-grid-pro-edit-text-field is just a vaadin-text-field with some custom styles).

Describe the solution you'd like

I would like to be able to set a custom webcomponent, maybe the html-tag would be enough.
The custom webcomponent ofc needs to fullfill a specific interface (needs to have a property value and a value-changed event).
Additionally it would be cool, if server-side components are supported as well, while still using the client-side api of the underlying webcomponent. That way, it would be possible to have server-side logic for the component, while the value would still be updated without a server roundtrip.

Describe alternatives you've considered

I've tried using the server-side custom component. Unfortunately they are limited to AbstractField at the moment (see #3023) and as mentioned earlier, the value of the editor is updated only after a server roundtrip.
I've also considered is to use the normal inline editing of the Grid. Unfortunately the editor is only activated after a server roundtrip, which drastically decreases the productivity of our users.
Another possible solution I tried was to use editor components to render the cells of the Grid, so that every (eitable) cell is an editor by default. We are using our own data binding so this solution would technically be possible. Unfortunately using ComponentRenderer for all cells drastically decreases the performance of the Grid and the LitRenderer API can't be used for all components we need as withFunction does not support return values.