Change type of `clk` to u32

[grjte]

Comment for the future: we frequently use u64 or usize for clk - but in our field, clk is guaranteed never to exceed a u32 value. I wonder if some point we should go through and update it everywhere to u32.

Originally posted by @bobbinth in https://github.com/maticnetwork/miden/pull/304#discussion_r919642358

[Dominik1999]

Can you assign me to it? It looks like I cannot do it myself.

[grjte]

Sure, it's yours. Thanks!

[grjte]

Just a note that for changes to the handling of the stack overflow table described in #347 the type won't be able to change to u32 in the stack module in the processor, so that one can be skipped.

If some changes are required in order to get all other changes in the codebase to compile, that will be fine - just keep it as minimal as possible, and I'll adjust the rest as I implement #347.

[bobbinth]

Closed by #376.