ve.dm.MWTemplateSpecModel: Expand parameter aliases

We were previously ignoring this data leading to situations
where a template that can be invoked like {{foo|1=bar}} and
{{foo|thing=bar}} (where the template data documents param
thing with alias '1') will show up in the editor with no
parameter information or label for the 1= call, but will show
up for the thing= call.

Now they are properly aliases so both will appear the same
in the editor dialog.

Bug: 49838
Change-Id: I37ec0e152df905844ac58ed1834fca29dccb4eec
Merge "ve.dm.MWTemplateSpecModel: Expand parameter aliases"