fftools/resources: Add resource manager files with build-time compression

Compression requires zlib to be available, otherwise resources will
be included uncompressed - in either case via BIN2C.

It can also be disabled via

./configure --disable-resource-compression

Size figures:

graph.css         7752
graph.css.min     6655 (css is always minified)
graph.html        2153

No Compression

graph.css.c      40026
graph.css.o       9344 (6688)
graph.html.c     13016
graph.html.o      4848 (2186)

With Compression

graph.css.c      10206
graph.css.o       4368 (1718)
graph.html.c      5725
graph.html.o      3632 (971)

Numbers in brackets: .rodata size from 'size -Ax -d *.o'

Signed-off-by: softworkz <softworkz@hotmail.com>

configure

@@ -523,6 +523,7 @@ Developer options (useful when working on FFmpeg itself):
   --enable-macos-kperf     enable macOS kperf (private) API
   --disable-large-tests    disable tests that use a large amount of memory
   --disable-ptx-compression don't compress CUDA PTX code even when possible
+  --disable-resource-compression don't compress resources even when possible
   --disable-version-tracking don't include the git/release version in the build
 
 NOTE: Object files are built at the place where configure is launched.
@@ -2123,6 +2124,7 @@ CONFIG_LIST="
     ossfuzz
     pic
     ptx_compression
+    resource_compression
     thumb
     valgrind_backtrace
     xmm_clobber_test
@@ -4179,6 +4181,7 @@ enable iamf
 enable large_tests
 enable optimizations
 enable ptx_compression
+enable resource_compression
 enable runtime_cpudetect
 enable safe_bitstream_reader
 enable static
@@ -6904,6 +6907,8 @@ EOF
 
 enabled zlib_gzip && enabled gzip || disable ptx_compression
 
+enabled zlib_gzip && enabled gzip || disable resource_compression
+
 # On some systems dynamic loading requires no extra linker flags
 check_lib libdl dlfcn.h "dlopen dlsym" || check_lib libdl dlfcn.h "dlopen dlsym" -ldl