HPCC-11667 Advanced menu falls behind nav bar

The advanced menu and search bar falls behind the navigation bar.
Utilize @media query to make items visible if under 960px resolution
which is 1024x768 screen resolution or if the browser window is scaled.

Signed-off by: Miguel Vazquez <miguel.vazquez@lexisnexis.com>
Merge pull request #6337 from miguelvazq/HPCC-11667

HPCC-11667 Advanced menu falls behind nav bar

Reviewed-By: Gordon Smith <gordon.smith@lexisnexis.com>
Reviewed-By: Richard Chapman <rchapman@hpccsystems.com>