Asset filter parameters use undefined on unselecting

[print-Sathvik]

Describe the bug
The values of asset type, asset status and asset class in asset filters is set as undefined when the "Select" option is selected from the dropdown.

To Reproduce
Steps to reproduce the behavior:

1. Go to https://care.coronasafe.in/assets
2. Select any option for asset class.
3. Clear the selection by selecting "Select" option(1st option)
4. Click on apply filter
5. The filtered asset count is 0 as there is no asset whose asset class is undefined

Expected behavior
The values of parameters should be set to empty strings when they are unselected from dropdown instead of undefined.