Resolve "allow maxThreads in the tomcat config to be configurable via values"

General MR

Summary

Adds an optional override for the min and max threads for the internal tomcat server for the ssc server. The values in values.yaml are the default values.

Relevant logs/screenshots

Defaults

helm template build chart/ | grep -A 5 "<Connector"
            <Connector maxThreads="4" minSpareThreads="1"
                    port="8080"
                    protocol="org.apache.coyote.http11.Http11Nio2Protocol"
                    server="Apache"
                    connectionTimeout="1000"
                    scheme="http"
--
            <Connector maxThreads="150" minSpareThreads="4"
                    port="8443"
                    protocol="org.apache.coyote.http11.Http11Nio2Protocol"
                    server="Apache"
                    connectionTimeout="10000"
                    connectionUploadTimeout="20000"

Overridden

helm template build chart/ --set ssc.config.http.max_threads=120 --set ssc.config.https.max_threads=99 | grep -A 5 "<Connector"
            <Connector maxThreads="120" minSpareThreads="1"
                    port="8080"
                    protocol="org.apache.coyote.http11.Http11Nio2Protocol"
                    server="Apache"
                    connectionTimeout="1000"
                    scheme="http"
--
            <Connector maxThreads="99" minSpareThreads="4"
                    port="8443"
                    protocol="org.apache.coyote.http11.Http11Nio2Protocol"
                    server="Apache"
                    connectionTimeout="10000"
                    connectionUploadTimeout="20000"

Relates #64 (closed)