Update networking layer w/ CURL and emscripten impl

External/curl-8.17.0/docs/libcurl/curl_global_cleanup.md

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+---
+c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
+SPDX-License-Identifier: curl
+Title: curl_global_cleanup
+Section: 3
+Source: libcurl
+See-also:
+  - curl_global_init (3)
+  - libcurl (3)
+  - libcurl-thread (3)
+Protocol:
+  - All
+Added-in: 7.8
+---
+
+# NAME
+
+curl_global_cleanup - global libcurl cleanup
+
+# SYNOPSIS
+
+~~~c
+#include <curl/curl.h>
+
+void curl_global_cleanup(void);
+~~~
+
+# DESCRIPTION
+
+This function releases resources acquired by curl_global_init(3).
+
+You should call curl_global_cleanup(3) once for each call you make to
+curl_global_init(3), after you are done using libcurl.
+
+This function is thread-safe since libcurl 7.84.0 if
+curl_version_info(3) has the CURL_VERSION_THREADSAFE feature bit set
+(most platforms).
+
+If this is not thread-safe, you must not call this function when any other
+thread in the program (i.e. a thread sharing the same memory) is running.
+This does not just mean no other thread that is using libcurl. Because
+curl_global_cleanup(3) calls functions of other libraries that are
+similarly thread unsafe, it could conflict with any other thread that uses
+these other libraries.
+
+See the description in libcurl(3) of global environment requirements for
+details of how to use this function.
+
+# CAUTION
+
+curl_global_cleanup(3) does not block waiting for any libcurl-created
+threads to terminate (such as threads used for name resolving). If a module
+containing libcurl is dynamically unloaded while libcurl-created threads are
+still running then your program may crash or other corruption may occur. We
+recommend you do not run libcurl from any module that may be unloaded
+dynamically. This behavior may be addressed in the future.
+
+libcurl may not be able to fully clean up after multi-threaded OpenSSL
+depending on how OpenSSL was built and loaded as a library. It is possible in
+some rare circumstances a memory leak could occur unless you implement your own
+OpenSSL thread cleanup. Refer to libcurl-thread(3).
+
+# %PROTOCOLS%
+
+# EXAMPLE
+
+~~~c
+int main(void)
+{
+  curl_global_init(CURL_GLOBAL_DEFAULT);
+
+  /* use libcurl, then before exiting... */
+
+  curl_global_cleanup();
+}
+~~~
+
+# %AVAILABILITY%
+
+# RETURN VALUE
+
+None