Add "pubapi" App Engine service for check API, WHOIS, and RDAP

The migration plan is as follows:
1. This CL, which adds the new "pubapi" service that serves the check API, WHOIS, and RDAP.
2a. Update our public facing sites to switch over to use the new service.
2b. (either order) Rewrite the check API to remove dependencies on flows.
3. ... eventually, once the frontend service is no longer being hit by this traffic, remove its handling of these public endpoints.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=197716346

java/google/registry/env/common/pubapi/WEB-INF/logging.properties

@@ -0,0 +1,13 @@
+# A default java.util.logging configuration.
+# (All App Engine logging is through java.util.logging by default).
+#
+# To use this configuration, copy it into your application's WEB-INF
+# folder and add the following to your appengine-web.xml:
+#
+# <system-properties>
+#   <property name="java.util.logging.config.file" value="WEB-INF/logging.properties"/>
+# </system-properties>
+#
+
+# Set the default logging level for all loggers to INFO.
+.level = INFO