feat: remove the use of mix-type fields for transportation access restrictions

[bastiaanvanassche-tomtom]

Based on:

• the slack conversation: https://overturemaps.slack.com/archives/C04NBKDE1DZ/p1700058876659019
• this draft PR from @ibnt1

this PR tackles the use of mix-type fields for transportation access restrictions

[vcschapp]

I'd like to discuss alternative names for accessType.

The merge-base changed after approval.

[vcschapp]

@bastiaanvanassche-tomtom Is it fair to say this PR captured what we wanted to do, but we never managed to merge it?

[vcschapp]

I'd like to discuss alternative names for accessType.

Can we change accessType to just access? It feels more right to me.

[vcschapp]

Plan agreed in the 2024-02-20 transportation TF main business meeting:

1. Bastiaan will resuscitate this PR, clear merge conflicts, get any needed approvals, and merge it.
2. After this, he will follow with two smaller PRs to make two adjustments:
   1. Rename accessType along the lines mentioned in this comment.
   2. Make the one-liner change to the combobulator to bring it into sync with the schema.

[vcschapp]

Plan agreed in the 2024-02-20 transportation TF main business meeting:

1. Bastiaan will resuscitate this PR, clear merge conflicts, get any needed approvals, and merge it.

2. After this, he will follow with two smaller PRs to make two adjustments:

   1. Rename accessType along the lines mentioned in this comment.
   2. Make the one-liner change to the combobulator to bring it into sync with the schema.

These TODOs are now tracked in https://github.com/OvertureMaps/tf-transportation/issues/101. So we really want to push to get this one reviewed and merged as-is.

[vcschapp]

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