Tranformer: Focus on input when adding formal transform
Tranformer: Focus on input when adding formal transform

Summary:
Sets the text input focus to the first textbox input on a tranformation
when a transformation is added in formal mode.

Test plan: visit test.html; set to formal mode; add each of the
transformations and verify that the first text box of the last
transformation is focused after creating each new transformation

Auditors: alex

ariabuckles/perseus,learningequality/perseus,alexristich/perseus,daukantas/perseus,huangins/perseus,ariabuckles/perseus,junyiacademy/perseus,iamchenxin/perseus,chirilo/perseus,alexristich/perseus,sachgits/perseus,iamchenxin/perseus,ariabuckles/perseus,learningequality/perseus,daukantas/perseus,sachgits/perseus,ariabuckles/perseus,junyiacademy/perseus,chirilo/perseus,abe4mvp/perseus,abe4mvp/perseus,huangins/perseus