[438280] Happy checkstyle and formatter

- Checkstyle rules changed to authorize javadoc on types without
authors, to keep the same rule as the formatter for the order of the
imports (with static ones).
- Formatter rules changed to have spaces only instead of tabs.
- Line delimiters converted to UNIX for all files.
- Format applied on custom source code.

Bug: 438280
Signed-off-by: Cedric Notot <cedric.notot@obeo.fr>