[ACTION] Update Linear OAuth components

We should add an optional prop to the Update Issue and Create Issue actions for the Linear OAuth app (slug = linear):

From their docs: https://developers.linear.app/docs/oauth/oauth-actor-authorization

To set the custom user name, set the createAsUser attribute with the user name and set displayIconUrl with the URL of the avatar in issueCreate or commentCreate mutations

We'll add the additional param to the authorization URL when these component changes are ready.

New optional prop:

• "Create As User" (default to true)
• If Create As User is true, set createAsUser to the user's displayName and displayIconUrl as avatarUrl (if not null). These can both be found by querying the user object (example below).
• If Create As User is false, then show 2 additionalProps:

1. Username (type string)
2. Display Icon URL (type string)

{ 
    user(id: "me") {
      displayName
      avatarUrl
    }
  }