daos: enhance use of lookup hash

lookup_insert_dir and associated functions have been
refactored and expanded.

*mfu_param_path.h*
- Added dfs_hash to mfu_file.
- Removed only_daos from mfu_file, since it is no longer needed

*Naming convention*
- Changed mfu_* to daos_* since they are only used by DAOS.
- Changed lookup_insert_dir to daos_lookup_hash.

*daos_lookup_hash and associated functions*
- Gets the hash from mfu_file instead of a global.
- Uses a pointer to the name instead of static allocation,
  which saves space.
- Updated error messages to use MFU_LOG instead of stderr directly.
- Added a _new and _delete function for the object handle struct.
- Properly deallocate and free each entry.

*daos_ IO functions*
With the excpetion of daos_opendir and daos_closedir,
all daos_ IO functions now use daos_hash_lookup to
get directory entries.

*mfu_util*
- Added daos_mount as a wrapper for dfs_mount.
- Added daos_umount as a wrapper for dfs_umount.
  This also destroys the hash.

*dcp.c*
Now uses the new daos_mount and daos_umount functions.

Signed-off-by: Dalton Bohning <daltonx.bohning@intel.com>

src/common/mfu_flist_copy.c

@@ -3171,10 +3171,10 @@ mfu_file_t* mfu_file_new(void)
     mfu_file_t* mfile = (mfu_file_t*) MFU_MALLOC(sizeof(mfu_file_t));
     mfile->type       = POSIX;
     mfile->fd         = -1;
-    mfile->only_daos  = false;
 #ifdef DAOS_SUPPORT
     mfile->obj        = NULL;
     mfile->dfs        = NULL;
+    mfile->dfs_hash   = NULL;
 #endif
     return mfile;
 }