php: fix php-config header file paths

Split outputs mean that the "include" folder from PHP gets placed into a
"dev" derivation. However php-config is not aware of this, which means
that compiling extensions with phpize fails with an error about being
unable to find header files (see #24357, #24420).  This fixes that by:

1. passing the `--includedir` flag to `configure` so that `php-config`
   gives the correct paths.

2. moving the `phpize` and `php-config` scripts and man pages to the
   dev derivation, to prevent cylic references.

3. ensuring that the `configure` script arguments are stripped from
   all binaries, including `php-embed`, to prevent cyclic references.