* Adds support for ETF constituent universes
* Adds filtering for universe data if it doesn't match the
universe subscription type
* Update mapping for ALL underlying Symbols if
`Symbol.UpdateMappedSymbol(...)` is called. Required to support
constituent ETF universes that might have mapping events
* Delistings of composite constituent universe Symbol will result in
removal of universe securities.
* Added regression algorithms for ETF constituent mappings (C#/Python),
along with data required to run locally
* Refactor universe delistings in SubscriptionSynchronizer -
big thank you to @Martin-Molinero :)
* Address review: update regression algorithms and add explanatory comments
* Address review: add additional checks to delisting regression algorithms
* Adds new regression algorithm testing the addition of a universe
without calling AddEquity() and asserts same behavior
Gerardo Salazar
cd9e451ead