CONFIGURE: added a configure option to add SONAME suffix

[roiedanino]

What?

Adds --with-soname-suffix option in configure which when set adds:

-release SUFFIX

for example:
libucp_la_LDFLAGS = -ldl -version-info $(SOVERSION) -release example

will produce:

libucp-example.so.0.0.0
libucp-example.so.0 -> libucp-example.so.0.0.0
libucp.so -> libucp-example.so.0.0.0

Why?

This allows creating purpose-specific .so files to avoid collisions with already loaded UCX versions when binding to specific versions or binaries is required.

This by itself won't provide a full isolation without using RTLD_DEEPBIND during dlopen.

[gleon99]

[P2] [important] Dotted suffixes break module loading

The option accepts dots, but libtool -release 1.22 produces names like libucs-1.22.so.0; UCX's module loader derives module_ext from the first dot in the loaded libucs basename, so it would look for module files ending in .22.so.0 instead of .so.0. That means accepted values such as --with-soname-suffix=1.22 can prevent optional UCT/UCM modules from loading. Either reject dots here or fix the loader to derive the real shared-library extension, and add a small configure/runtime check for a dotted suffix.

[gleon99]

[P2] [important] libucs_signal is left unsuffixed

The new suffix is applied to libucm/libucs/libuct/libucp, but libucs_signal is also an installed versioned UCX shared library. If the goal is avoiding collisions with already-loaded UCX DSOs, leaving this SONAME as libucs_signal.so.0 keeps one UCX entry point outside the suffix scheme. Add $(UCX_LT_RELEASE) here as well, or explicitly document that this option is limited to the four core libraries.