Fix issue with duplicate ids in workspace tree block field menus.
Fix issue with duplicate ids in workspace tree block field menus.

mark-friedman/blockly,rachel-fenichel/blockly,daarond/blockly,lzairdking/blockly,mark-friedman/blockly,twodee/blockly,griffpatch/scratch-blocks,google/blockly,carlosperate/blockly,markocelan/blockly-minecraft,twodee/blockly,twodee/blockly,lzairdking/blockly,sclements/scratch-blocks,nickmain/blockly,trinketapp/blockly,google/blockly,nickmain/blockly,trinketapp/blockly,jstnhuang/blockly,mark-friedman/blockly,gengshenghong/scratch-blocks,trodi/blockly,picklesrus/blockly,markocelan/blockly-minecraft,joshlory/blockly,jstnhuang/blockly,picklesrus/blockly,groklearning/blockly,dhalupa/blockly,sclements/scratch-blocks,joshlory/blockly,dhalupa/blockly,google/blockly-devtools,groklearning/blockly,google/blockly,trodi/blockly,hkoi/blockly,trinketapp/blockly,sclements/scratch-blocks,rachel-fenichel/blockly,google/blockly,trodi/blockly,hkoi/blockly,jano42/blockly,daarond/blockly,markocelan/blockly-minecraft,nickmain/blockly,rachel-fenichel/blockly,rachel-fenichel/blockly,griffpatch/scratch-blocks,google/blockly,gengshenghong/scratch-blocks,LLK/scratch-blocks,mark-friedman/blockly,jano42/blockly,LLK/scratch-blocks,twodee/blockly,carlosperate/blockly,twodee/blockly,trodi/blockly,InspectorWidget/blockly,LLK/scratch-blocks,joshlory/blockly,rachel-fenichel/blockly,hkoi/blockly,mark-friedman/blockly,InspectorWidget/blockly,nickmain/blockly,LLK/scratch-blocks,jano42/blockly,dhalupa/blockly,aravart/speech-blocks,griffpatch/scratch-blocks,sclements/scratch-blocks,sclements/scratch-blocks,google/blockly-devtools,nickmain/blockly,jstnhuang/blockly,lzairdking/blockly,carlosperate/blockly,google/blockly,griffpatch/scratch-blocks,lzairdking/blockly,google/blockly,gengshenghong/scratch-blocks,gengshenghong/scratch-blocks,picklesrus/blockly,InspectorWidget/blockly,rachel-fenichel/blockly,LLK/scratch-blocks,twodee/blockly,rachel-fenichel/blockly,groklearning/blockly,aravart/speech-blocks,groklearning/blockly,carlosperate/blockly,nickmain/blockly,jstnhuang/blockly,jano42/blockly,mark-friedman/blockly,markocelan/blockly-minecraft,gengshenghong/scratch-blocks,trinketapp/blockly,griffpatch/scratch-blocks,daarond/blockly