Improve counts on record page table of contents

[jrchudy]

The count on record page for related tables in the left panel (table of contents) represents the number of records that are visible for the loaded page of results and a + if there are more rows. We should improve this to update as the user has seen more rows from the related table.

For instance, say we have 31 rows for a related table and the page size for the related table is 10. The following is how the count should be represented as the user pages through that related table:

• When the record page loads, related table is on "page 1" and count is shown as 10+
• User pages the related table using next and now sees "page 2", count should be shown as 20+
• User pages again using next and sees "page 3", count should be shown as 30+
• User pages once more and sees the last page, count should be shown as 31

If the user pages back using previous, the count should remain the same since we have already seen that previous page.

If at any point, the content of the related table is fetched again and changes, this count state should be reset. This might only occur if rows are deleted by someone else while the user is looking at this page.