cgen: fix fixed array of map type

[felipensp]

Fix #18342

🤖 Generated by Copilot at 5920e41

This pull request adds support for fixed arrays of maps in the V language. It modifies the checker.v and array.v files to handle the type checking and code generation for this feature, and adds a test file fixed_array_map_test.v to verify its functionality.

🤖 Generated by Copilot at 5920e41

• Add support for fixed arrays of maps in the checker and the C backend (link, link)

• Check if the type symbol of a variable is a fixed array and register it in the table (checker.v, link)
• Generate C code for initializing each map element of a fixed array with an empty map (array.v, link)

• Add a test function for fixed arrays of maps (fixed_array_map_test.v, link)