feat: restructure mock module and separate its codebase into a new crate

.changelog/unreleased/features/954-restructure-mock-module-into-crate.md

@@ -0,0 +1,3 @@
+- Restructure the mock module implementation and separate its codebase into a
+  new crate named `ibc-testkit`
+  ([\#954](https://github.com/cosmos/ibc-rs/issues/954))

.changelog/unreleased/improvements/951-remove-default-portid.md

@@ -0,0 +1,2 @@
+- Remove the default value and implementation for `PortId`
+  ([\#951](https://github.com/cosmos/ibc-rs/pull/951))

.changelog/unreleased/improvements/952-expose-channel-message-types copy.md

@@ -0,0 +1,2 @@
+- Expose domain message types under the `ics04_channel` as public
+  ([\#952](https://github.com/cosmos/ibc-rs/pull/952))

Cargo.toml

@@ -5,6 +5,7 @@ resolver = "2"
 members = [
     "crates/ibc",
     "crates/ibc-derive",
+    "crates/ibc-testkit",
     "crates/ibc-query",
 ]
 

README.md

@@ -29,10 +29,11 @@ the `ibc` rust crate which defines the main data structures and on-chain logic f
 ## Libraries
 
 - [ibc](crates/ibc/README.md) - Data structures and on-chain logic for the IBC protocol.
-- [ibc-query](crates/ibc-query/README.md) - Utility traits and implementations for querying the
-state of an `ibc-rs` enabled chain.
 - [ibc-derive](crates/ibc-derive/README.md) - Derive macros for `ClientState`
   and `ConsensusState` traits, reducing boilerplate.
+- [ibc-testkit](crates/ibc-testkit/README.md) - Testing toolkit to aid ibc-rs and host chains for writing integration tests
+- [ibc-query](crates/ibc-query/README.md) - Utility traits and implementations for querying the
+state of an `ibc-rs` enabled chain.
 
 ## Contributing