add CTA archive backend

Add the CTA archive to ESAP.

esap/esap/configuration/esap_cta.py

+#import requests
+#import urllib.parse
+#import json
+
+title = "cta"
+logo = "https://upload.wikimedia.org/wikipedia/commons/d/d1/Cherenkov_Telescope_Array_logo.jpg"
+
+# definition of the query
+query_schema = {
+    "name": "cta",
+    "title": "CTA Query",
+    "type": "object",
+    "properties": {
+        "particle": {
+            "type": "string",
+            "title": "particle",
+            "default": "proton",
+            "enum": ["proton","gamma-diffuse"],
+            "enumNames": ["Proton","Gamma-diffuse"]
+        },
+        #"keyword": {
+        #    "type": "string",
+        #    "title": "keyword",
+        #},
+        "catalog": {
+            "type": "string",
+            "title": "Catalog",
+            "enum": ["cta"],
+            "enumNames": ["Cta"]
+        }
+    }#,
+    #"required": ["community"]
+}
+#ui_schema = {"keyword": {"ui:help": "e.g. CTA", "ui:placeholder": "optional"}, "catalog": {"ui:widget": "hidden"}}
+ui_schema = {#"keyword": {"ui:help": "e.g. CTA"}, 
+	      #"particle": {"ui:placeholder": "Proton"},
+	      "catalog": {"ui:widget": "hidden"}}
+