Manual overrides for form component `text-area` characterCounter not displaying correctly

[trbmcginnis]

In order to customize the maximum value on the character counter for text-area components, we should be able to override the default 2000 when invoking the text-area component by setting @maxlength to whichever number we want. This is currently not working and instead the number remains the default 2000.

On text-area component:

<CharacterCounter
  @string={{@value}}
  @maxlength={{if @maxlength @maxlength '2000'}}
/>

When invoking:

<form.Field
        @type="text-area"
        @attribute="dcpProjectsitedescription"
        @maxlength="2400"
  />

^^ this still displays as 0/2000