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/sync_rule_nested_projects/nested.project.json

@@ -1,12 +0,0 @@
-{
-  "name": "nested",
-  "tree": {
-    "$path": "src"
-  },
-  "syncRules": [
-    {
-      "pattern": "*.txt",
-      "use": "ignore"
-    }
-  ]
-}