feat: add template file metadata types in file.rs module

Add comprehensive template file metadata representation with:
- File struct for storing template metadata (path, format, engine type)
- Engine enum (Static, Tera) for template processing type detection
- Format enum (Yml, Toml, Tf, Tera) for output format identification
- Extension enum for supported file extensions
- Robust error handling with thiserror for file parsing errors
- Extensive test coverage (46 test cases) for edge cases and validation
- Support for both static files and Tera templates with inner format detection

This provides a standardized way to represent and validate template files
without handling actual rendering or I/O operations.

Author: josecelano

Cargo.toml

@@ -32,4 +32,5 @@ serde = { version = "1.0", features = [ "derive" ] }
 serde_json = "1.0"
 tempfile = "3.0"
 tera = "1.0"
+thiserror = "1.0"
 torrust-linting = { path = "packages/linting" }

project-words.txt

@@ -38,5 +38,9 @@ Tera
 terraformrc
 tfstate
 tfvars
+thiserror
 tlsv
 usermod
+значение
+ключ
+конфиг