MODE-2259 Fixed the WebApp handlers.

Since the requirement is to be able to deploy WARs from within our EAP subsystem, the only way I was able to figure out how to do this is via the `DeploymentAddHandler` which only works in the `MODEL` stage.

The solution was to check in our handlers the `requiresRuntime(context)` and only perform the model change & invoke the handler for a "NORMAL" server.
Taken from the WF API:
```
  protected boolean requiresRuntime(OperationContext context) {
        return context.isNormalServer();
    }
```
and 
```
/**
     * Convenience method to check if the {@link #getProcessType() process type} is {@link ProcessType#isServer() a server type}
     * and the {@link #getRunningMode() running mode} is {@link RunningMode#NORMAL}. The typical usage would
     * be for handlers that are only meant to execute on a normally running server, not on a host controller
     * or on a {@link RunningMode#ADMIN_ONLY} server.
     *
     * @return {@code true} if the {@link #getProcessType() process type} is {@link ProcessType#isServer() a server type}
     *         and the {@link #getRunningMode() running mode} is {@link RunningMode#NORMAL}.
     */
 boolean isNormalServer();
```