Use of Cognito "PoolName" in Events Can Associate Function with Incorrect/Unexpected Cognito User Pool

When using a "PoolName" as the mechanism by which to associate a Lambda Function Event with a Cognito User Pool it is possible to associate a Lambda Function with an unexpected/incorrect User Pool. The cause of this issue is that User Pool Names are not guaranteed to be unique and the impact is that lambda functions can be triggered unexpectedly.

service: service

provider:
  name: aws
  region: us-west-2
  runtime: nodejs12.x
  stage: ${opt:stage}

functions:
  functionname:
    handler: function.handler
    events:
      - cognitoUserPool:
          existing: true
          # "poolname" is not guaranteed to be unique
          # resulting in a situation where his event/function could
          # be associated with an unexpected CognitoUserPool
          pool: poolname
          trigger: UserMigration

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Service Information
service: service
stage: dev
region: us-west-2
stack: stack
resources: 9
api keys:
  None
endpoints:
  None
functions:
  user-migration: function
layers:
  None
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Installed version

Framework Core: 2.1.1
Plugin: 4.0.4
SDK: 2.3.2
Components: 3.1.3