add APIs for dash docs testings

[byronz]

Start with a description of this PR. Then edit the list below to the items that make sense for your PR scope, and check off the boxes as you go!

Contributor Checklist

• I have broken down my PR scope into the following TODO tasks
  • add timeout argument in process runner
  • add wait_for_element_by_id
• I have run the tests locally and they passed. (refer to testing section in contributing)

optionals

• I have added entry in the CHANGELOG.md
• If this PR needs a follow-up in dash docs, community thread, I have mentioned the relevant URLS as follow
  • this github #PR number updates the dash docs

[alexcjohnson]

Looks great, turning those hard-coded timeouts into params is 💰
💃

[alexcjohnson]

💃 again :)