Fix issues with showing failed @test results

[omus]

Fixes a variety of issues found while working on #22296

julia> using Base.Test

julia> x, y, z = 1:3;

julia> @test x ≈ y
Test Failed
  Expression: x ≈ y
   Evaluated: 1 isapprox 2
ERROR: There was an error during testing

julia> @test x == y == z
Test Failed
  Expression: $(Expr(:escape, :x)) $(Expr(:escape, :(==))) $(Expr(:escape, :y)) $(Expr(:escape, :(==))) $(Expr(:escape, :z))
   Evaluated: 1 == 2 == 3
ERROR: There was an error during testing