Invalid URLs are created by MetaAddEditLinkColumn when using QueryString argument type and existing url already has query string parameters

[vex]

When using QMetaControlArgumentType::QueryString? url's rather than pathinfo, and using a datagrid with an edit button, the resulting URL that MetaAddEditLinkColumn? creates is invalid if the existing querystring already contains query parameters. Example:

<?php 
$this->dtgUsers->MetaAddEditLinkColumn('index.php?page=edit_user', 'Edit', 'Edit', QMetaControlArgumentType::QueryString); 
?>

Results in the Edit button having the URL of index.php?page=edit_user?intId=6

To fix this meta_add_edit_column.tpl needs to be modified to check whether the URL string already has existing parameters or not.

I've included a patch file for includes/qcubed/_core/codegen/templates/db_orm/meta_datagrid/meta_add_edit_column.tpl with the necessary change (not sure what patch file format it should be though!).

[VexedPanda]

Re-rolled the patch in standard format

[alex94040]

Code review looks good; check it in!

[VexedPanda]

(In [872]) Fixes #472 in v1.1 and v2.0