Index values, fixed income quotes, and global corporate actions

Market Data API

Expands the Market Data API with index values, latest fixed income quotes, and global corporate actions support:

Adds GET /v1beta1/indices/latest/values for the latest index values and GET /v1beta1/indices/values for paginated historical index values, filterable via the new index_symbols parameter.
Adds GET /v1beta1/fixed_income/latest/quotes for the latest fixed income quotes, with a new trade_size parameter.
Adds a region filter to GET /v1/corporate-actions via the new cas_region parameter, accepting us, non_us, or all (default us).
Adds isin and currency fields across the corporate action schemas, including forward and reverse splits, cash and stock dividends, mergers, spin-offs, name and symbol changes, rights distributions, redemptions, unit splits, and worthless removals.