Update data_class_*_var templates (properties templates) to deal with overridden properties (open and override modifiers)

Author: macisamuele

gradle-plugin/plugin/src/main/resources/kotlin/data_class_opt_var.mustache

@@ -1 +1 @@
-    @Json(name = "{{{baseName}}}") @field:Json(name = "{{{baseName}}}") {{#vendorExtensions.x-nullable}}@XNullable {{/vendorExtensions.x-nullable}}var {{{name}}}: {{#isEnum}}{{{datatypeWithEnum}}}{{/isEnum}}{{^isEnum}}{{{datatype}}}{{/isEnum}} = {{#defaultvalue}}{{defaultvalue}}{{/defaultvalue}}{{^defaultvalue}}null{{/defaultvalue}}
+    @Json(name = "{{{baseName}}}") @field:Json(name = "{{{baseName}}}") {{#vendorExtensions.x-nullable}}@XNullable {{/vendorExtensions.x-nullable}}{{#isInherited}}override {{/isInherited}}{{#hasChildren}}open {{/hasChildren}}var {{{name}}}: {{#isEnum}}{{{datatypeWithEnum}}}{{/isEnum}}{{^isEnum}}{{{datatype}}}{{/isEnum}} = {{#defaultvalue}}{{defaultvalue}}{{/defaultvalue}}{{^defaultvalue}}null{{/defaultvalue}}

gradle-plugin/plugin/src/main/resources/kotlin/data_class_req_var.mustache

@@ -1 +1 @@
-    @Json(name = "{{{baseName}}}") @field:Json(name = "{{{baseName}}}") var {{{name}}}: {{#isEnum}}{{{datatypeWithEnum}}}{{/isEnum}}{{^isEnum}}{{{datatype}}}{{/isEnum}}
+    @Json(name = "{{{baseName}}}") @field:Json(name = "{{{baseName}}}") {{#isInherited}}override {{/isInherited}}{{#hasChildren}}open {{/hasChildren}}var {{{name}}}: {{#isEnum}}{{{datatypeWithEnum}}}{{/isEnum}}{{^isEnum}}{{{datatype}}}{{/isEnum}}