Remove the type union from goog.soy.TextTemplate
Remove the type union from goog.soy.TextTemplate

This type union interferes with type checking which in turn hides real errors.  I plan on following up and removing the rest.

RELNOTES: goog.soy.TextTemplate typedef has dropped support for the legacy third parameter.

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Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=254442799

google/closure-library,lucidsoftware/closure-library,google/closure-library,google/closure-library,lucidsoftware/closure-library,lucidsoftware/closure-library,google/closure-library,google/closure-library,lucidsoftware/closure-library