fs/ntfs3: implement iomap-based file operations

fs/ntfs3: implement iomap-based file operations

This patch modifies the ntfs3 driver by replacing the buffer_head-based
operations with the iomap ones.

Implementation details:
- Implements core iomap operations (ntfs_iomap_begin/end) for block mapping:
    Proper handling of resident attributes via IOMAP_INLINE.
    Support for sparse files through IOMAP_HOLE semantics.
    Correct unwritten extent handling for zeroing operations.
- Replaces custom implementations with standardized iomap helpers:
    Converts buffered reads to use iomap_read_folio and iomap_readahead.
    Implements iomap_file_buffered_write for write operations.
    Uses iomap_dio_rw for direct I/O paths.
    Migrates zero range operations to iomap_zero_range.
- Preserves special handling paths for compressed files
- Implements proper EOF/valid data size management during writes

Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>