add kwarg to test for approximate symmetric/hermitian matrices

[bjarthur]

closes #28885. see recent comments

[dkarrasch]

Suggested change

	* `issymmetric` and `ishermitian` can now test for approximate equality
	* `issymmetric` and `ishermitian` can now test for approximate symmetry

?

[dkarrasch]

How would we deal with the tolerance keywords to isapprox? I guess only via a lambda like

issymmetric(A, eq=((x, y) -> isapprox(x, y, atol=..., rtol=...)))

? With so much code, I wonder what is wrong about isapprox(A, A', atol=..., rtol=...), or, if there is no need for special tolerances, A ≈ A'.

[N5N3]

Comment from another related issue:
I think that isapprox(X, transpose(X), atol=atol, rtol=rtol) is definitely more reasonable here than an element-wise test. Probably should also pass through a norm argument.
Originally posted by @stevengj in #36243 (comment)

[bjarthur]

hah. hadn't thought of simply doing isapprox(A,A'). that suffices for me so i'll close this PR.