Add custom debug impl for Capabilities<Flag> (#2186)

* custom debug impl

* just the flag name

* core debug

* no std

* this is it

sdk/src/types/block/capabilities.rs

@@ -32,7 +32,7 @@ impl From<Infallible> for CapabilityError {
 }
 
 /// A list of bitflags that represent capabilities.
-#[derive(Debug, Deref)]
+#[derive(Deref)]
 #[repr(transparent)]
 pub struct Capabilities<Flag> {
     #[deref]
@@ -58,6 +58,12 @@ impl<Flag> Capabilities<Flag> {
     }
 }
 
+impl<Flag: CapabilityFlag> core::fmt::Debug for Capabilities<Flag> {
+    fn fmt(&self, f: &mut core::fmt::Formatter<'_>) -> core::fmt::Result {
+        f.debug_list().entries(self.capabilities_iter()).finish()
+    }
+}
+
 impl<Flag: CapabilityFlag> Capabilities<Flag> {
     /// Try to create capabilities from serialized bytes. Bytes with trailing zeroes are invalid.
     pub fn from_bytes(bytes: impl Into<Box<[u8]>>) -> Result<Self, CapabilityError> {
@@ -234,7 +240,7 @@ impl<Flag: 'static + CapabilityFlag> Packable for Capabilities<Flag> {
     }
 }
 
-pub trait CapabilityFlag {
+pub trait CapabilityFlag: core::fmt::Debug {
     type Iterator: Iterator<Item = Self>;
 
     /// Converts the flag into the byte representation.