Update project configuration and snapshot files

- Changed the default project file from `plugin.project.json` to `plugin.project.json5` in `build.rs`.
- Added new project configuration files in JSON5 format for various test cases, including `default.project.json5`, `client_in_folder`, `csv_bug_145`, and others.
- Updated snapshot files to reflect changes in instance structure and properties, ensuring consistency with the new project configurations.
- Removed unnecessary script and module instances from snapshot files to streamline the testing process.

rojo-test/build-tests/issue_546/README.md

@@ -1,2 +1,2 @@
 # Issue #546 (https://github.com/rojo-rbx/rojo/issues/546)
-Regression from Rojo 6.2.0 to Rojo 7.0.0. Meta files named as init.meta.json should apply after init.client.lua and other init files.
+Regression from Rojo 6.2.0 to Rojo 7.0.0. Meta files named as init.meta.json5 should apply after init.client.luau and other init files.