Integrate configuration into tracking

[shantanuraj]

:star2: What does this PR do?

• 📦 Add get_active_config to TrackConfig
• 🌟 Prefill time-entry using active config

:bug: Recommendations for testing

• This PR implements part 3 of the spec described in #45.
• We use the active configuration implemented in #53 as defaults for our time-entry.
• Not sure if we should do the following in this PR or as a follow-up.
  • Create missing entities (projects and tasks) if they don't exist.
  • Fetch workspaces as part of Entities and implement default matching for configuration.

Commands affected

$ toggl config active
$ toggl start
$ toggl start --interactive

See it in action

https://github.com/watercooler-labs/toggl-cli/assets/1716853/d6772c86-0c4d-4128-9564-1fd96a22a7cb

:memo: Links to relevant issues/docs

See #45 for the configuration proposal.

:speech_balloon: Summarise how you feel about this PR with a gif/image