THRIFT-5855: Add rust fuzzers

Add fuzzers for Rust support, to improve the reliability/robustness of the implementation
diff --git a/lib/rs/test/fuzz/.gitignore b/lib/rs/test/fuzz/.gitignore
new file mode 100644
index 0000000..80ed2f8
--- /dev/null
+++ b/lib/rs/test/fuzz/.gitignore
@@ -0,0 +1,6 @@
+target
+corpus
+artifacts
+coverage
+lib/fuzz_test.rs
+Cargo.lock
\ No newline at end of file