Add missing fossils for gen iv

[Machine-Maker]

Change description

• Closes Gen IV fossils seem to be missing from encounter data #1475
• Added all fossils for Gen IV games (all 5).
• Added 2 new location areas, the museums in the 2 regions
• Added 2 new encounter condition values for the 2 fossil items that didn't exist.

AI coding assistance disclosure

Used claude code to analyze the csv files to help me understand the structure and identify ids of existing elements to re-uses.

Contributor check list

• I have written a description of the contribution and explained its motivation.
• I have written tests for my code changes (if applicable).
• I have read and understood the AI Assisted Contribution guidelines.
• I will own this change in production, and I am prepared to fix any bugs caused by my code change.

[Naramsim]

Hi! To me it looks fine but I didn't check the data/v2/csv/encounter_condition_value_map.csv and data/v2/csv/encounters.csv file. If @notblisy or @ItsMeJoji have some time maybe they could help us here