[TSVB] [Table tab] "Math" aggregation not working for Table view

[alexwizp]

"Math" aggregation not working at all for table view.

Steps to reproduce:

1. Open TSVB and go to Table tab
2. Configure some Math aggregation like e.g
   

Expected result:
Table should contain some data

Actual result:

Console log:

   │ proc [kibana] TypeError: extractFields is not a function
   │ proc [kibana]     at getSplits (/Users/Documents/Kibana/src/plugins/vis_type_timeseries/server/lib/vis_data/helpers/get_splits.js:26:46)
   │ proc [kibana]     at /Users/Documents/Kibana/src/plugins/vis_type_timeseries/server/lib/vis_data/response_processors/series/math.js:30:26
   │ proc [kibana]     at next (/Users/Documents/Kibana/src/plugins/vis_type_timeseries/server/lib/vis_data/response_processors/table/math.js:14:12)
   │ proc [kibana]     at next (/Users/Documents/Kibana/src/plugins/vis_type_timeseries/server/lib/vis_data/response_processors/table/std_sibling.js:17:47)
   │ proc [kibana]     at /Users/Documents/Kibana/src/plugins/vis_type_timeseries/server/lib/vis_data/response_processors/table/std_metric.js:43:12
   │ proc [kibana]     at runMicrotasks (<anonymous>)
   │ proc [kibana]     at processTicksAndRejections (internal/process/task_queues.js:95:5)
   │ proc [kibana]     at /Users/Documents/Kibana/src/plugins/vis_type_timeseries/server/lib/vis_data/table/process_bucket.js:50:30
   │ proc [kibana]     at async Promise.all (index 0)
   │ proc [kibana]     at /Users/Documents/Kibana/src/plugins/vis_type_timeseries/server/lib/vis_data/table/process_bucket.js:28:20
   │ proc [kibana]     at async Promise.all (index 0)
   │ proc [kibana]     at getTableData (/Users/Documents/Kibana/src/plugins/vis_type_timeseries/server/lib/vis_data/get_table_data.ts:100:20)
   │ proc [kibana]     at async Promise.all (index 0)
   │ proc [kibana]     at /Users/Documents/Kibana/src/plugins/vis_type_timeseries/server/routes/vis.ts:36:23
   │ proc [kibana]     at Router.handle (/Users/Documents/Kibana/src/core/server/http/router/router.ts:273:30)
   │ proc [kibana]     at handler (/Users/Documents/Kibana/src/core/server/http/router/router.ts:228:11)

[elasticmachine]

Pinging @elastic/kibana-app (Team:KibanaApp)