Fix bug where Query parser ignored 0 strings

[stnguyen90]

When Query::parse() parsed a string like equal("attr", [0]) it ignored the 0 string so the values was an empty array. This caused a 500 error in Appwrite.

appwrite  | array(1) {
appwrite  |   [0]=>
appwrite  |   object(Utopia\Database\Query)#1556 (3) {
appwrite  |     ["method":protected]=>
appwrite  |     string(5) "equal"
appwrite  |     ["attribute":protected]=>
appwrite  |     string(7) "intAttr"
appwrite  |     ["values":protected]=>
appwrite  |     array(0) {
appwrite  |     }
appwrite  |   }
appwrite  | }
appwrite  | [Error] Type: Utopia\Exception
appwrite  | [Error] Message: Error handler had an error
appwrite  | [Error] File: /usr/src/code/vendor/utopia-php/framework/src/App.php

Related issue:

• 🐛 Bug Report: Server Error (500) when searching (Query.equal("x", 0)) for 0 in an interger field appwrite/appwrite#3926

[eldadfux]

Looks good, left one small comment. 👍

[eldadfux]

leftover