Filters defined via the 'extraParams' option are applied but they don't show up in the filter row

Steps to reproduce:

• In a page containing a livetable, add a filter on one of the declared columns via the 'extraParams' option. Example: 'extraParams': '&doc.author=e' (this will search for all pages authored by a user whose username contains an 'e').
• The livetable results are filtered as expected.

Expected result:

• The filter widget of the column titled 'Last author' in the table filters row should display the applied filter (e.g. letter 'e' in our example).
• The URL fragment should reflect the applied filter. (e.g '|t=livetable&p=1&l=15&doc.author=e')

Actual result:

• The filter widget of the filtered column remains empty. This makes it impossible for the user to remove the applied filter.
• The URL fragment does not reflect the applied filter either.