In RY-962, we've noted it was too slow to search requirements per lower key.
We'll add a column "UPPERKEY" where we'll store the uppercase requirement key, for search.

Risks

• It may take some space in the database to store both KEY and UPPERKEY (but it is worth it for indexing),

• The two values may become unsynchronized if we program wrongly. Currently, both values are set using the same method, we need to keep it this way.