Feature internal 56 me tdataio validate payload (#346)

* Internal issue #56 XML schema for validating to prevent DoS via large payload, recursive payloads, ill-formed XML specification file

* schema for validating the payload (recursive, excessively large)

* Delete METdbLoad/ush/specification_schema.xsd

* internal issue #56 validating payload using XML schema

* internal issue #56 invalid XML spec files used to test XML validation

* internal issue #56 add the location of the XML schema file to be used in validating the XML specification file

* internal issue #56 tests added to verify validation code is providing expected results

* internal issue#56 added new fixture used in testing XML validation code

* fix import for read_load_xml module

* removed extraneous ',' in import

* Working version but still needs to check for recursive payloads for some elements

* Valid XML that is used for real-world data and is valid XML

* Change the name of the XML schema file

* Use the full_example.xml file instead of the test_load_specification.xml for testing against a valid XML file

* Delete METdbLoad/ush/load_specification.xsd

* Test for recursive payload in load_val fields

* Added test for recursion under the load_val complex type

* Change values to prevent recursive payloads and remove defunct regex

* Remove unused imports, add test for recursion under the load_val fields

* Add some extra elements

* Add more recursive elements to trigger ValueError

* skip testing the recursion in load_val

* Remove limit to number of load_val elements

* Fixed incorrect skip syntax

* Reinstate the maxOccurs and minOccurs for the field

* Update temporary XML spec file to match load_specification_schema.xsd

* Config file for testing recursive payload in the fields element

* Work-in-progress.  Recursive payloads checked for some elements but no checking for large payloads

* Added test for recursive payload for fields (in addition to test for recursive val elements)

* Update tests and test config files

* Additional test configuration files

* updated schema, now working

* modified test configuration file

* Allow '-' in regex for limited string type

* Updated file so it is valid with respect to the schema

* Include testing one of the xml specification files used in testing two databases

* Reformat code for easier reading, update the load_met_gha_new.xml file to be valid

* include testing the load_met_gha_new.xml file

* Updated: reformatted and updated to conform to schema

* Added an extra date_list element

* added testing xml specification file with more than one date_list

* Clean up unnecessary comments

* Update number of date_list items

* Explicitly set minLength and maxLength for hostname, db name, password, etc.

* allow password to be string type and limit length of password

* comment out mysql commands. ci-run-all-cases

* Fix comment

* Remove main function with hard-coded paths. Only useful during development.

* Add support for line_type element

* Added line_type element and some values for example xml specification

* use the linetype type for the line_type to enforce expected characters and string lengths

METdbLoad/ush/load_specification_schema.xsd

@@ -161,7 +161,7 @@
                             <xs:element name="line_type" minOccurs="0" maxOccurs="1">
                                <xs:complexType>
                                   <xs:sequence>
-                                     <xs:element type="xs:string" name="val" maxOccurs="800" minOccurs="0"/>
+                                     <xs:element type="linetype" name="val" maxOccurs="800" minOccurs="0"/>
                                   </xs:sequence>
                                </xs:complexType>
                             </xs:element>