[lldb/Symbol] Fix column breakpoint `move_to_nearest_code` match

This patch fixes the column symbol resolution when creating a breakpoint
with the `move_to_nearest_code` flag set.

In order to achieve this, the patch adds column information handling in
the `LineTable`'s `LineEntry` finder. After experimenting a little, it
turns out the most natural approach in case of an inaccurate column match,
is to move backward and match the previous `LineEntry` rather than going
forward like we do with simple line breakpoints.

The patch also reflows the function to reduce code duplication.

Finally, it updates the `BreakpointResolver` heuristic to align it with
the `LineTable` method.

rdar://73218201

Differential Revision: https://reviews.llvm.org/D101221



Signed-off-by: Med Ismail Bennani <medismail.bennani@gmail.com>