Client: Refactor Engine API (#3291)

* Move engine.ts to dedicated engine API code folder

* Move types to dedicated types.ts file

* Move validators to a dedicated validators.ts file

* Add dedicated util.ts file, move first two methods

* Move next two methods to util.ts

* Move last remaining methods to util.ts

* Move CLConnectionManager from generic util folder to engine API RPC folder

* Adjust test paths

* Move validator initialization in Engine API constructor to dedicated private method

* Some additional initValidators() structuring and documentation

* Move util.ts to dedicated util folder, rename to generic.ts

* Adjust paths

* Add call-specific util files

* Delete accidentally re-checked in util.ts file

* Move first two methods to dedicated per-call util files

* Move remaining per-call methods to dedicated util files

* Add new validate4844BlobVersionedHashes helper

* Better newPayload documentation

* Better forkchoiceUpdate documentation, additional structuring

* Additional documentation and Engine API doc references for remaining API calls

packages/client/src/rpc/util/CLConnectionManager.ts → packages/client/src/rpc/modules/engine/CLConnectionManager.ts

@@ -1,17 +1,17 @@
 import { Hardfork } from '@ethereumjs/common'
 
-import { Event } from '../../types'
-import { short, timeDiff } from '../../util'
+import { Event } from '../../../types'
+import { short, timeDiff } from '../../../util'
 
-import type { Config } from '../../config'
+import type { Config } from '../../../config'
 import type {
   ExecutionPayloadV1,
   ExecutionPayloadV2,
   ExecutionPayloadV3,
   ForkchoiceResponseV1,
   ForkchoiceStateV1,
   PayloadStatusV1,
-} from '../modules/engine'
+} from './types'
 import type { Block } from '@ethereumjs/block'
 import type winston from 'winston'