adding synonyms set to filters (#2515)

Author: l-trotta

output/schema/schema.json

@@ -113,6 +113,7 @@ export class SynonymGraphTokenFilter extends TokenFilterBase {
   lenient?: boolean
   synonyms?: string[]
   synonyms_path?: string
+  synonyms_set?: string
   tokenizer?: string
   updateable?: boolean
 }
@@ -124,6 +125,7 @@ export class SynonymTokenFilter extends TokenFilterBase {
   lenient?: boolean
   synonyms?: string[]
   synonyms_path?: string
+  synonyms_set?: string
   tokenizer?: string
   updateable?: boolean
 }