Adds support for search egress span name too

[jcchavezs]

Currently the search for span names in a service work only for ingress. This feels like a broken experience as it is usually easer to now the caller (which does the egress) rather than the callee (which does the ingress). Most of tracing UIs support this too.

[kotharironak]

Can you add more details like e.g? Are you suggesting that search should also allow for egress records?