Improve expression equivalence in presence of dep-types

src/main/scala/inox/ast/SymbolOps.scala

src/main/scala/inox/ast/TypeOps.scala

src/main/scala/inox/ast/Types.scala

src/main/scala/inox/solvers/unrolling/LambdaTemplates.scala

...cala/inox/solvers/unrolling/QuantificationTemplates.scala