UPI&ISIN : CFI : FX : REST : Add CFI Array component on all impacted products

[anjdelapena]

The DSB have been asked to look at alternatives for the delivery of CFI changes:
(1) The RoC had concerns that a further revision of the CFI standard might be issued by the CFI maintenance agency before the CFI 2021 project is delivered in Q1 2025.
(2) The DSB has received user feedback from the adoption of the UPI into the ISIN service which challenges the approach being taken by the original CFI 2021 technical design.

The revised approach agreed with the TAC and the PC now is to deliver a new CFI Service that will separate the CFI code derivation from the core Identifier system simplifying the maintenance required when adopting a new revision of the CFI standard.

This update provides a specification for the array structure that supports CFI 2015 and 2021 codes, along with the attributes and values for both UPI and OTC ISIN services, specifically within the FX asset class in the REST environment.