fix(model-server): configure websockets connections to be more robust

Increase default timeout to be consistent with the LightModelServer.
Enable pinging to keep connection alive.
Set maxFrameSize and masking explicitly to not be affected by changing defaults

Author: Oleksandr Dzhychko

model-server/src/main/kotlin/org/modelix/model/server/Main.kt

@@ -34,6 +34,8 @@ import io.ktor.server.routing.Routing
 import io.ktor.server.routing.get
 import io.ktor.server.routing.routing
 import io.ktor.server.websocket.WebSockets
+import io.ktor.server.websocket.pingPeriod
+import io.ktor.server.websocket.timeout
 import kotlinx.html.a
 import kotlinx.html.h1
 import kotlinx.html.li
@@ -61,6 +63,7 @@ import java.io.FileReader
 import java.io.FileWriter
 import java.io.IOException
 import java.nio.charset.StandardCharsets
+import java.time.Duration
 import javax.sql.DataSource
 
 object Main {
@@ -157,7 +160,12 @@ object Main {
                 install(Routing)
                 installAuthentication(unitTestMode = !KeycloakUtils.isEnabled())
                 install(ForwardedHeaders)
-                install(WebSockets)
+                install(WebSockets) {
+                    pingPeriod = Duration.ofSeconds(30)
+                    timeout = Duration.ofSeconds(30)
+                    maxFrameSize = Long.MAX_VALUE
+                    masking = false
+                }
                 install(ContentNegotiation) {
                     json()
                 }