feat: add date as an option for field types

[RangerMauve]

Closes #317

Adds date as a valid type for Fields. Do we need good/bad docs for this? Didn't see anything for other types of fields.

[achou11]

Does there need to be some kind of encoding/decoding validation to ensure the value is a valid ISO string?

[achou11]

Just to confirm: is it unnecessary/useless to (de)serialize values as date objects? My initial thought is that it doesn't make sense in our case because there's an IPC boundary that potentially doesn't handle that well (e.g. I don't think rpc-reflector handles dates)

[achou11]

Do we need good/bad docs for this? Didn't see anything for other types of fields.

It's pretty limited, but there are a couple of good doc fixtures:

comapeo-schema/test/fixtures/good-docs-completed.js

Lines 193 to 218 in d78ffe0

	{
	doc: {
	docId: cachedValues.docId,
	versionId: cachedValues.versionId,
	originalVersionId: cachedValues.originalVersionId,
	schemaName: 'field',
	createdAt: cachedValues.createdAt,
	updatedAt: cachedValues.updatedAt,
	links: [],
	tagKey: 'otherTagKey',
	type: 'number',
	label: 'differentLabel',
	appearance: 'singleline',
	snakeCase: true,
	universal: true,
	options: [
	{
	label: 'someOtherLabel',
	value: 'somePrimitiveTagValue',
	},
	],
	helperText: '',
	deleted: false,
	},
	expected: {},
	},

comapeo-schema/test/fixtures/good-docs-minimal.js

Lines 53 to 69 in d78ffe0

	{
	doc: {
	docId: cachedValues.docId,
	versionId: cachedValues.versionId,
	originalVersionId: cachedValues.originalVersionId,
	schemaName: 'field',
	createdAt: cachedValues.createdAt,
	updatedAt: cachedValues.updatedAt,
	links: [],
	tagKey: 'myTagKey',
	label: 'my label',
	type: 'text',
	deleted: false,
	universal: false,
	},
	expected: {},
	},

[RangerMauve]

There's no existing hooks for validating values in fields (tags in an observation / track) right now so I think we can put it off until it's on our roadmap.

Just to confirm: is it unnecessary/useless to (de)serialize values as date objects?

Affirmative it is not necessary right now, we might do it later in the year but it's not on the TODO list right now.