Refactor how IgxGrid uses the IgxPaginator

[hanastasov]

Description

Currently the igx-grid exposes proxy properties and methods (page, perPage, paginate) to control the IgxPaginator that is used internally.

Also, the grid emits the onPagingDone event, while the paginator does not.

For any input/output handling, a dev should place the paginator in a template and do all handling through the paginator itself. Grid does not need to expose proxy properties/methods/outputs no more.

• igniteui-angular version: 11.1

Tasks

• Paginator to expose missing events: paging, pagingDone
• Remove grid onPagingDone output
• Deprecate proxy members in the grid (page, perPage, paginate, nextPage, previousPage)
• Any corrections needed in the grid paging pipe, if broken with the changes
• Decide if external paginator will be used the same way as now ([pagingTemplate]="pager"), or shall be placed inside the grid, similarly to the igx-toolbar
• Write migrations