Fixed a bug with trigraphs and digraphs

[5BNeumann]

norminette/rules/check_preprocessor_indent.py does: spaces = context.peek_token(i).line_column - hash_.line_column - 1 to count the spaces after the # (or the ??= trigraph/%: digraph). This is flawed since digraphs and trigraphs are more than one character long.
Instead, we should probably count spaces as such:

        n = context.skip_ws(i)
        spaces = 0
        while context.check_token(i, "SPACE"):
            i += 1
            spaces += 1
        if context.check_token(i, "TAB"):
            context.new_error("TAB_REPLACE_SPACE", context.peek_token(i))
        while context.check_token(i, "TAB"):
            i += 1
            spaces += 1
        i = n

Sadly, this does induces overhead in the introduction of the second while loop that accounts for tabs.

Verification Steps

Please ensure the following steps have been completed:

• Added new tests to cover the changes.
• Fixed all broken tests.
• Ran poetry run flake8 to check for linting issues.
• Verified that all unit tests are passing:
  • Ran poetry run pytest to ensure unit tests pass.
  • Ran poetry run tox to validate compatibility across Python versions.