grass.script: Add Python type hints to core.py (OSGeo#7130)

Author: Sourish-spc

python/grass/script/core.py

@@ -1839,7 +1839,7 @@ def parse_color(
 # check GRASS_OVERWRITE
 
 
-def overwrite():
+def overwrite() -> bool:
     """Return True if existing files may be overwritten"""
     owstr = "GRASS_OVERWRITE"
     return owstr in os.environ and os.environ[owstr] != "0"
@@ -1848,7 +1848,7 @@ def overwrite():
 # check GRASS_VERBOSE
 
 
-def verbosity():
+def verbosity() -> int:
     """Return the verbosity level selected by GRASS_VERBOSE
 
     Currently, there are 5 levels of verbosity:
@@ -2212,7 +2212,7 @@ def debug_level(force: bool = False, *, env: _Env = None):
 # TODO: Remove the pygrass backwards compatibility version of it?
 
 
-def legal_name(s):
+def legal_name(s: str) -> bool:
     """Checks if the string contains only allowed characters.
 
     This is the Python implementation of :func:`G_legal_filename()` function.