[router] add reasoning parser base structure (#9310)

Co-authored-by: Chang Su <chang.s.su@oracle.com>

sgl-router/src/reasoning_parser/mod.rs

@@ -0,0 +1,7 @@
+pub mod factory;
+pub mod parsers;
+pub mod traits;
+
+pub use factory::{ParserFactory, ParserRegistry};
+pub use parsers::BaseReasoningParser;
+pub use traits::{ParseError, ParserResult, ReasoningParser};