add support for eml file parser (#1768)

### What problem does this PR solve?

add support for eml file parser
#1363

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

---------

Co-authored-by: Zhedong Cen <cenzhedong2@126.com>
Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

web/src/components/chunk-method-modal/hooks.ts

@@ -27,7 +27,7 @@ const ParserListMap = new Map([
       'one',
       'qa',
       'manual',
-      'knowledge_graph',
+      'knowledge_graph'
     ],
   ],
   [
@@ -67,6 +67,7 @@ const ParserListMap = new Map([
   ],
   [['md'], ['naive', 'qa', 'knowledge_graph']],
   [['json'], ['naive', 'knowledge_graph']],
+  [['eml'], ['email']]
 ]);
 
 const getParserList = (