Refactor for GRAM (ex TON) integration

- Updated imports and references from TON to GRAM across multiple modules.
- Renamed functions and variables to reflect the change from TON to GRAM.
- Adjusted validation checks for top-up and recharge amounts to use GRAM limits.
- Modified error messages and exceptions to indicate GRAM instead of TON.
- Updated tests to ensure they reflect the new GRAM terminology and functionality.
- Introduced new constants for GRAM-related configurations.

.gitignore

@@ -37,3 +37,7 @@ systests/
 dist/
 build/
 *.egg-info/
+uv.lock
+
+#docs
+*-docs/