Suggestion: lower the default `array-size-threshold`/make `large_const_arrays` apply to all large consts

I've been looking into performance issues with debug builds of Symphonia, and it seems it's largely caused by indexing a large lookup table (const [f32; 512]) in a loop, which causes the entire table to be copied each iteration.

This would have been caught earlier by clippy::large_const_arrays if the default threshold was lower.

I see 162 projects on github using array-size-threshold<1kB, indicating that a lot of people prefer to use a smaller threshold.

Lowering the default might cause the clippy::large_stack_arrays lint to be triggered more often, so it might be a good idea to have a different threshold for each lint.

Also, would it make sense for large_const_arrays to lint all consts larger than array-size-threshold? Because currently, this is caught:

pub const a: [u32; 1_000_000] = [0u32; 1_000_000];

but not this:

pub const a: ([u32; 1_000_000],) = ([0u32; 1_000_000],);