Dimension check too restrictive in copytrito! and lacpy!

[amontoison]

In #51909, I interfaced copytri! and lacpy!, but I didn't test them on rectangular matrices. The check:

(m1 < m || n1 < n) && throw(DimensionMismatch(lazy"B of size ($m1,$n1) should have at least the same number of rows and columns as A of size ($m,$n)"))

is too restrictive in two cases.

1. If A has more rows than columns and uplo = 'U', B only needs to be p x p, where p is the number of columns of A. A common application of this is performing a reduced QR on A.

2. Similarly, if A has more columns than rows and uplo = 'L', B only needs to be t x t, where t is the number of rows of A. This is relevant when performing a reduced LQ on A.