model : Maincoder-1B support (#18534)

* Add Maincoder model support

* Removed SPM model vocabulary setting and MOE related GGUF parameters
Removed trailing spaces from maincoder.cpp

* removed set_vocab

* added new line

* Fix formatting

* Add a new line for PEP8

src/CMakeLists.txt

@@ -87,6 +87,7 @@ add_library(llama
             models/llada.cpp
             models/llama-iswa.cpp
             models/llama.cpp
+            models/maincoder.cpp
             models/mamba.cpp
             models/mimo2-iswa.cpp
             models/minicpm3.cpp