Revert "[REF] use generic loadStandardSearchOptionsFromUrl". Fix search selections.

Revert "[REF] use generic loadStandardSearchOptionsFromUrl". Fix search selections.

Overview
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This reverts commit a5ca2ad8e16b145edf3a5604fab923d1e2386b37
and fixes a bug in management of the prev/next cache. The
bug is visible when following this procedure:

1. In browser, use "Quick search" to search for text "am"
2. In browser, select checkboxes next to two items
3. In MySQL CLI, run `select * from civicrm_prevnext_cache where is_selected =1;`
4. In browser, continue to next page. Observe that there are no more selection.
5. In MySQL CLI, re-run SQL query. Observe that the selections have disappeared.

Before
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Proceeding to another page of search results causes loss of selections

After
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Selections are preserved