migrated the frontend file generation, changed folder structure

backend/src/request_response_models.py

@@ -0,0 +1,17 @@
+from pydantic import BaseModel
+
+
+class ConvertRequest(BaseModel):
+    text: str
+    format: str  # e.g. "mol", "smi", "sdf", "inchi", etc.
+    add_hydrogen: bool = False
+    convert_3d: bool = False
+    optimize_geometry: bool = False
+
+
+class MolFileModel(BaseModel):
+    molfile: str
+
+
+class BasicError(BaseModel):
+    error: str