Retain original param names and ignore leading/trailing whitespace

Objectives:

* Trim leading or trailing whitespace that parsoid may have left on
  parameter names
* Preserve the original name for round-tripping cleanliness
* Ignore leading or trailing whitespace when entering new parameter names
  in the parameter search widget
* Consider aliases when listing suggested parameters

Changes:

ve.ui.MWParameterSearchWidget.js
* Use hasParameter method instead of using indexOf - uses map lookup
  internally, which is much faster, and also take aliases into account
* Trim query input value to prevent leading or trailing whitespace from
  being considered when filtering known or creating unknown parameters
* Take aliases into account when showing filtered results

ve.dm.MWTransclusionModel.js
* Use original name when round-tripping

ve.dm.MWTemplateParameterModel.js
* Store original name for round tripping, and trim the original name for
  other uses
* Add getOriginalName method

ve.dm.MWTemplateModel.js
* Add hasParameter method, which currently just does a map lookup, but can
  do other processing in the future

ve.dm.MWTemplateSpecModel.js
* Add isParameterKnown method

Bug: 50715
Bug: 50717
Change-Id: I36a5e93ca8938ac3401a6e274647597704700468
Merge "Retain original param names and ignore leading/trailing whitespace"