these unused includes were identifier by clang-include-cleaner. after
auditing these source files, all of the reports have been confirmed.
please note, because quite a few source files relied on
`utils/to_string.hh` to pull in the specialization of
`fmt::formatter<std::optional<T>>`, after removing
`#include <fmt/std.h>` from `utils/to_string.hh`, we have to
include `fmt/std.h` directly.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
To be used to force usage of source_dc, even
when it is unsafe for rebuild.
Update docs and add test/nodetool/test_rebuild.py
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Clearly indicate if a source_dc is provided,
and if so, was it explicitly given by the user,
or was implicitly selected by scylla.
This will become useful in the next patches
that will use that to either reject the operation
if it's unsafe to use the source_dc and the dc was
explicitly given by the user, or whether
to fallback to using all nodes otherwise.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>