Setup optional telemetry authorization

[quesabe]

Closes PLA-277.

If telemetry endpoint requires authorisation, it can be provided in form of a header. Two additional options are defined:

• header name,
• GitHub secret name to pull the token from.

[linear]

PLA-277

[gvidon]

@quesabe would this make naming more consistent?

Suggested change

	headers[authHeaderName] = process.env[telemetryAuthToken]!
	headers[reportTargetAuthHeaderName] = process.env[reportTargetAuthToken]!

Also let's probably rename project.telemetryReportUrl to project.reportTargetUrl.

[quesabe]

@gvidon Updated the option names.

BTW, since we added more options shouldn't we move them into an object instead of residing them all on the root of the options. E.g.:

export interface TelemetryOptions {
  /**
   * Endpoint URL to send telemetry data to.
   */
  readonly reportTargetUrl?: string

  /**
   * Authorization header name for telemetry
   */
  readonly reportTargetAuthHeaderName?: string

  /**
   * The name of env var to extract header value from.
   * The value is expected to be stored in a CI secret.
   */
  readonly reportTargetAuthTokenVar?: string
}

export interface WithTelemetry {
  /**
   * Enable template usage telemetry.
   * Collects the data on the template package version, connected git remotes,
   * applied escape hatches, configured GitHub workflows.
   *
   * @default false
   */
  readonly isTelemetryEnabled?: boolean

  /**
   * Configuration options for telemetry
   */
  readonly telemetryOptions?: TelemetryOptions
}

[gvidon]

@quesabe yeah, an object is a good idea. Should we add it per this PR?

[quesabe]

I see it's merged. Let me create a separate one.

[quesabe]

Also added a commit that removes any logic related to parent-subproject relation, since we aim for projenrc file that is only present on root project in a nested setup.