Bug 14029: Provide 'clear' link to empty reports search filters

Bug 14029: Provide 'clear' link to empty reports search filters

Patch adds a 'clear' link next to the 'Apply filters' button to
empty out the form fields.

To test:
- go to the reports module
- make sure you have some saved reports
- search your saved reports using the author, keyword and date filters
- verify searching works as expected
- verify the new 'clear' link works as expected

Tested couner patch, followed test plan, works as expected. QA tools ok.
Signed-off-by: Marc Véron <veron@veron.ch>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@unc.edu.ar>