Raise LengthInvalid (not RangeInvalid) for non-sized values in Length

[uttam12331]

Summary

Length.__call__ raises LengthInvalid for its length checks, but the except TypeError handler raises RangeInvalid:

def __call__(self, v):
    try:
        if self.min is not None and len(v) < self.min:
            raise LengthInvalid(self.msg or 'length of value must be at least %s' % self.min)
        if self.max is not None and len(v) > self.max:
            raise LengthInvalid(self.msg or 'length of value must be at most %s' % self.max)
        return v
    # Objects that have no length e.g. None or strings will raise TypeError
    except TypeError:
        raise RangeInvalid(self.msg or 'invalid value or type')   # <-- should be LengthInvalid

When a value with no len() (e.g. None, or an int) is passed to a Length validator, the error is reported as a range error rather than a length error — inconsistent with the validator's own two other error paths.

This looks like a copy-paste leftover from the Clamp validator directly above, which is genuinely a range operation and correctly raises RangeInvalid in its own except TypeError.

Fix

     except TypeError:
-        raise RangeInvalid(self.msg or 'invalid value or type')
+        raise LengthInvalid(self.msg or 'invalid value or type')

LengthInvalid is already imported at the top of the module.

Tests

Tightened test_length_invalid to assert the raised error is a LengthInvalid. It fails on the previous behavior (RangeInvalid) and passes with the fix. Full suite: 181 passed.