fix sha1 digest type

[mmitti]

In boost 1.86, changing boost::uuids::detail::sha1::digest_type int[5] to char[20]. I was compile current code with MSVC2022, i got compile errors due to those change. So, I fix to folloup those changes to pass compile.

ref: boostorg/uuid@0f84313#diff-8a0985025af60846be9c809585d2659b4e3d5de04714ff76d174b80aaa719c97

[pdimov]

This fix is slightly incorrect, because digest[i] is unsigned char and is output as a character to buf, instead as an integer, as intended.

#893 fixes it.
#892 adds a test for the sha1 class. The test passes for 1.85, and after #893.

Additionally, #891 is a small change to the test Jamfile that makes the tests link under Windows as well.