PR #20198, "Do not alter soft wrap based on .editorconfig contents"
removed support for setting line lengths for both soft and hard wrap,
not just soft wrap. This causes the `max_line_length` property within a
`.editorconfig` file to be ignored by Zed. This commit restores allowing
for hard wrap limits to be set using `max_line_length` without impacting
soft wrap limits. This is done by merging the `max_line_length` property
from an editorconfig file into Zed's `preferred_line_length` property.

Release Notes:

- Added support for .editorconfig's `max_line_length` property

Signed-off-by: Ryan Drew <git@ry4n.me>