Graph autocomplete limited to selected host in Graphs page

In page Monitoring->Hosts->Graphs autocomplete for filter field Graph should show only graphs, that are present for selected host.

• If host is not selected, autocomplete should show graphs from any host.
• This fix should not change Graph multiselect behavior in other pages, except Monitoring->Hosts->Graphs
• Change of host in Host multiselect should not change already selected graphs in Graphs multiselect.
• Should affect both 'Strict' and 'Pattern' search types.