lib: Expand ostree static-delta show to show part stats

Now we display stats on the individual parts, such as the blob size
and the number of each type of opcode.  Most interesting to me is
things like how many bsdiff opcodes there are vs new objects, etc.

src/libostree/ostree-repo-static-delta-private.h

@@ -109,6 +109,17 @@ typedef enum {
   OSTREE_STATIC_DELTA_OPEN_FLAGS_VARIANT_TRUSTED = (1 << 1)
 } OstreeStaticDeltaOpenFlags;
 
+typedef enum {
+  OSTREE_STATIC_DELTA_OP_OPEN_SPLICE_AND_CLOSE = 'S',
+  OSTREE_STATIC_DELTA_OP_OPEN = 'o',
+  OSTREE_STATIC_DELTA_OP_WRITE = 'w',
+  OSTREE_STATIC_DELTA_OP_SET_READ_SOURCE = 'r',
+  OSTREE_STATIC_DELTA_OP_UNSET_READ_SOURCE = 'R',
+  OSTREE_STATIC_DELTA_OP_CLOSE = 'c',
+  OSTREE_STATIC_DELTA_OP_BSPATCH = 'B'
+} OstreeStaticDeltaOpCode;
+#define OSTREE_STATIC_DELTA_N_OPS 7
+
 gboolean
 _ostree_static_delta_part_open (GInputStream   *part_in,
                                 GBytes         *inline_part_bytes,
@@ -123,10 +134,16 @@ gboolean _ostree_static_delta_dump (OstreeRepo     *repo,
                                     GCancellable   *cancellable,
                                     GError        **error);
 
+typedef struct {
+  guint n_ops_executed[OSTREE_STATIC_DELTA_N_OPS];
+} OstreeDeltaExecuteStats;
+
 gboolean _ostree_static_delta_part_execute (OstreeRepo      *repo,
                                             GVariant        *header,
                                             GVariant        *part_payload,
                                             gboolean         trusted,
+                                            gboolean         stats_only,
+                                            OstreeDeltaExecuteStats *stats,
                                             GCancellable    *cancellable,
                                             GError         **error);
 
@@ -142,16 +159,6 @@ gboolean _ostree_static_delta_part_execute_finish (OstreeRepo      *repo,
                                                    GAsyncResult    *result,
                                                    GError         **error); 
 
-typedef enum {
-  OSTREE_STATIC_DELTA_OP_OPEN_SPLICE_AND_CLOSE = 'S',
-  OSTREE_STATIC_DELTA_OP_OPEN = 'o',
-  OSTREE_STATIC_DELTA_OP_WRITE = 'w',
-  OSTREE_STATIC_DELTA_OP_SET_READ_SOURCE = 'r',
-  OSTREE_STATIC_DELTA_OP_UNSET_READ_SOURCE = 'R',
-  OSTREE_STATIC_DELTA_OP_CLOSE = 'c',
-  OSTREE_STATIC_DELTA_OP_BSPATCH = 'B'
-} OstreeStaticDeltaOpCode;
-
 gboolean
 _ostree_static_delta_parse_checksum_array (GVariant      *array,
                                            guint8       **out_checksums_array,