Added mongo helper to input serializers

refs #10922

This helper assits in replaces keys and values as defined by the mapping object

core/server/api/v2/utils/serializers/input/utils/mongo.js

@@ -0,0 +1,44 @@
+const _ = require('lodash');
+const nql = require('@nexes/nql');
+
+/*
+ * Returns the replacement value for input, or input if it doesn't exist
+ */
+function replaceValue(input, valueMappings) {
+    const replacer = valueMappings.find(({from}) => from === input);
+    return replacer && replacer.to || input;
+}
+
+function fmap(item, fn) {
+    return Array.isArray(item) ? item.map(fn) : fn(item);
+}
+
+function mapKeysAndValues(input, mapping) {
+    return nql.utils.mapQuery(input, function (value, key) {
+        // Ignore everything that has nothing to do with our mapping
+        if (key !== mapping.key.from) {
+            return {
+                [key]: value
+            };
+        }
+
+        // key: valueA
+        if (typeof value !== 'object') {
+            return {
+                [mapping.key.to]: replaceValue(value, mapping.values)
+            };
+        }
+
+        // key: { "$in": ['valueA', 'valueB'] }
+        // key: { "$ne": 'valueA' }
+        return {
+            [mapping.key.to]: _.reduce(value, (memo, objValue, objKey) => {
+                return Object.assign(memo, {
+                    [objKey]: fmap(objValue, item => replaceValue(item, mapping.values))
+                });
+            }, {})
+        };
+    });
+}
+
+module.exports.mapKeysAndValues = mapKeysAndValues;