bt2: field.py: raise ValueError when setting out of range value to Integer

bt2: field.py: raise ValueError when setting out of range value to Integer

This commit removes the use of `utils._check_int64()` and
`utils._check_uint64()` methods as the validity of the value is now
checked using the _check_range() method and the existing field class'
`_field_value_range` setter property.

Signed-off-by: Francis Deslauriers <francis.deslauriers@efficios.com>
Change-Id: Ib5b33ae5becc9f71b20b17ae0244b6e676b89f75
Reviewed-on: https://review.lttng.org/c/babeltrace/+/2081
Tested-by: jenkins <jenkins@lttng.org>