Add pagination for search channels

[meKushdeepSingh]

Problem

In channel screen, when a user searches with a keyword that can yield multiple results, only the results from the first page are displayed. Pagination does not work when searching for channels.

Found 3 more issues:

1. Normal pagination occasionally skips one or two pages when loading the next page.
2. If a user selects another category and performs a search using a keyword, the app activates all categories and conducts the search. However, if the user clears the text from the search bar, the results should appear for all categories. Instead, the app displays all categories as selected but shows results for the previously selected category.
3. There is a UX issue with the pagination loader.