[Request] Add support to subpath on the Webapp

[MrFabio]

Currently, the chart allows the configuration of the hostname for several services:

api.hostname:     api-sip-customer-site.com      or  api.sip.customer.site.com
grafana.hostname: grafana-sip-customer-site.com  or  grafana.sip.customer.site.com
homer.hostname:   homer-sip-customer-site.com    or  homer.sip.customer.site.com
jaeger.hostname:  jaeger-sip-customer-site.com   or  jaeger.sip.customer.site.com
webapp.hostname:  webapp-sip-customer-site.com   or  webapp.sip.customer.site.com

It will create an Ingress + External IP for each one (if enabled). It would be nice to add the possibility to use just 1 ingress with subpaths for each service, like so:

api.hostname:     customer.site.com/sip/api
grafana.hostname: customer.site.com/sip/grafana
homer.hostname:   customer.site.com/sip/homer
jaeger.hostname:  customer.site.com/sip/jaeger
webapp.hostname:  customer.site.com/sip/webapp

With this, we can only use 1 External IP and reduce the number of firewall rules. By making the solution cheaper overall.

Another issue the chart won't solve is the webapp to support the resources not being on the root. It doesn't allow setting a custom/relative path for the new "root". I experienced similar problems with Homer webapp.