build: install the public headers under iceberg/catalog (#927)

rest_catalog.h is installed and includes iceberg/catalog/session_catalog.h,
but the CMake build never installs the headers directly under
src/iceberg/catalog, so any downstream project that consumes the installed
package and uses the REST catalog fails to compile:

  fatal error: iceberg/catalog/session_catalog.h: No such file or directory

The Meson build already installs these three headers; only CMake is missing
them, and every sibling directory (data, expression, manifest, ...) calls
iceberg_install_all_headers.

Author: plusplusjiajia

src/iceberg/catalog/CMakeLists.txt

@@ -15,6 +15,8 @@
 # specific language governing permissions and limitations
 # under the License.
 
+iceberg_install_all_headers(iceberg/catalog)
+
 add_subdirectory(memory)
 
 if(ICEBERG_BUILD_REST)