[Enhancement]: Allow specifying if an Equity Comp Cancellation transaction is considered a forfeiture?

[jacobyavis]

Description of Enhancement :

The EquityCompensationCancellation should have an additional field to describe the type of cancellation.
Three options:
FORFEITURE
EXPIRATION
OTHER

Why is this Needed?

There's a desire to be able to distinguish when an Equity Compensation Cancellation is a forfeiture, or an expiration, or other.

Anything else we need to know?

Created while working through the comments sheet attached to issue #507

[jacobyavis]

TWG Notes Sep 12
-- a second option would be to create three different event types -- forfeiture event, expiration event, and cancellation event
-- a third option would be to try to make an implicit rule based on the grant type, but there may not be a clean 1:1 way of doing that

Thoughts being that if there not a true full overlap between the different types, then they should be modelled as three separate transactions.

Further thinking suggests the shape is probably the same for all three different types, so this might actually be best implemented as a "flavour" on the cancellation