(proof of concept) Show tls library name in status

[michaelortmann]

Found by: https://github.com/michaelortmann
Patch by: https://github.com/michaelortmann
Fixes:

One-line summary:
Show tls library name in status

Additional description (if needed):
This could also fix .status showing something like:
Tcl library: //zipfs:/lib/tcl/tcl_library
instead of the name/path of the tcl lib
dladdr() is not POSIX, but it is available under solaris, linux and bsd and we can autoconf for it.

Test cases demonstrating functionality (if applicable):
.status
Before:

[...]
Tcl library: /usr/lib/tcl8.6
Tcl version: 8.6.16 (header version 8.6.16)
Tcl is threaded.
TLS support is enabled.
TLS library: OpenSSL 3.6.0 1 Oct 2025 (header version OpenSSL 3.6.0 1 Oct 2025)
[...]

After:

[...]
Tcl library: /usr/lib/tcl8.6
Tcl version: 8.6.16 (header version 8.6.16)
Tcl is threaded.
TLS support is enabled.
TLS library: /usr/lib/libssl.so.3
TLS version: OpenSSL 3.6.0 1 Oct 2025 (header version OpenSSL 3.6.0 1 Oct 2025)
[...]

TODO: additional, testing with static linking and windrop