add minimum value spec for maxrec param

add simplistic {table name},{location} regex pattern for upload param

Author: pdowler

openapi/dali-maxrec.yaml

@@ -4,3 +4,5 @@ description: request a specific limit on number of rows to return
 schema:
     type: integer
     format: int64
+    minimum: 0
+    exclusiveMinimum: false

openapi/dali-upload.yaml

@@ -5,3 +5,6 @@ description: |
   uploaded and used in the request
 schema:
     type: string
+    # {table name},{location}
+    # pattern is {1+ word characters},{1+ non-whitespace characters}
+    pattern: '^\w+,\S+$'