Imply DateFormatTokens based on Temporal or epochTimestamp

[dotCipher]

When handling SlackDateTime we should have a more simple implementation that accepts a single parameter and 'imply' the format based on the granularity (or if fields are supported).

We should use the ChronoUnit on the resulting Temporal#isSupported or we can use a simple Temporal type map to Set<DateFormatToken>

[dotCipher]

Blocked on #16 merge (and related)