Standardise location of test noir programs

[TomAFrench]

We currently have test programs spread out in various directories:

• compiler/integration_tests/circuits
• compiler/wasm/fixtures
• tooling/nargo_cli/tests
• tooling/noir_js/tests
• tooling/noir_codegen/tests

Much of these are unnecessary and just result in duplication and potential annoying CI footguns where someone forgets to update a committed build artifact which results in a test passing/not passing appropriately.

We should move these up to a test_programs directory in the monorepo root which we can then have as a reusable source of test programs.