feature/clippy clean

[zacchiro]

This makes the code base "cargo clippy" clean and enable pre-commit check on clippy.

Please review a few things before merging:

• The test backends::buffered_bit_stream_writer::test_buffered_bit_stream_writer is failing, but that was already the case in branch main.
• I've explicitly ignored with "let _" I/O return values that were previously ignored silently. (It should change nothing performance-wise, but maybe you do want to check those values...)
• I've allowed unneeded casts in a generated function, because that cast that clippy is complaining about is actually unneeded or not depending on the type instanciation. (And I don't think we want to go as far as checking that in the code generator...)

Merging this PR would fix #3.

[zacchiro]

On Sun, May 21, 2023 at 10:46:10AM -0700, Sebastiano Vigna wrote:

• if USE_TABLE {
• if delta_tables::write_table_be(self, value)? {
• return Ok(());
• }
• if USE_TABLE && delta_tables::write_table_be(self, value)? {

I have a problem here because USE_TABLE is really conditional compilation and mixing it with runtime code is ugly. I like that there is a clear conditional box and inside there's code. I guess there's no way to convince Clippy that a nested if with a constant value is OK, in which case I'd convince Clippy (at least for this crate) that nested if's are OK.

Fair enough. Is it better now with fe6e0177bde269af948073ef781fe88c8fc8baae ?

[vigna]

OMG a bit fine grained but let's go 😂