Remove the unused field types from the fields package

[timleslie]

See #5025.

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🦋 Changeset detected

Latest commit: dda1ae0

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 15 packages

Name	Type
@keystone-next/fields-legacy	Major
@keystone-next/fields-auto-increment-legacy	Patch
@keystone-next/fields-cloudinary-image-legacy	Patch
@keystone-next/fields-color-legacy	Patch
@keystone-next/fields-location-google-legacy	Patch
@keystone-next/fields-markdown-legacy	Patch
@keystone-next/fields-mongoid-legacy	Patch
@keystone-next/fields-oembed-legacy	Patch
@keystone-next/fields-unsplash-legacy	Patch
@keystone-next/fields-wysiwyg-tinymce-legacy	Patch
@keystone-next/api-tests-legacy	Patch
@keystone-next/benchmarks-legacy	Patch
@keystone-next/fields-document	Patch
@keystone-next/fields	Patch

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