scylla_cql: Publish methods needed for tests

Those constructors are needed for users that want to utilize our type
ser / deser functionality more directly.

Author: Lorak-mmk

scylla-cql/src/deserialize/frame_slice.rs

@@ -139,7 +139,7 @@ impl<'frame> FrameSlice<'frame> {
     ///
     /// If the operation fails then the slice remains unchanged.
     #[inline]
-    pub(super) fn read_cql_bytes(
+    pub fn read_cql_bytes(
         &mut self,
     ) -> Result<Option<FrameSlice<'frame>>, LowLevelDeserializationError> {
         // We copy the slice reference, not to mutate the FrameSlice in case of an error.

scylla-cql/src/deserialize/row.rs

@@ -29,10 +29,7 @@ impl<'frame, 'metadata> ColumnIterator<'frame, 'metadata> {
     /// - `specs` - information about columns of the serialized response,
     /// - `slice` - a [FrameSlice] which points to the serialized row.
     #[inline]
-    pub(crate) fn new(
-        specs: &'metadata [ColumnSpec<'metadata>],
-        slice: FrameSlice<'frame>,
-    ) -> Self {
+    pub fn new(specs: &'metadata [ColumnSpec<'metadata>], slice: FrameSlice<'frame>) -> Self {
         Self {
             specs: specs.iter().enumerate(),
             slice,