[NKI] nki beta 2 integration (pt 1. dtypes)

[latentCall145]

Summary

adds dtype support to the dtypes that the NKI Beta 2 interpreter uses

Test Plan

tests added to make sure floats are rounded to the right values based on dtype (test_dtypes.py)

Related Issues

NKI Beta 2 interpreter: #296

Breaking Changes

N/A

Checklist

• I added tests to all new functionality I added/bugs I fixed.
• I verified that a human has reviewed all code in this PR.
• I ran npm run build:frontend if the PR modified any TypeScript code.
• I made sure that my code is well documented (comments explaining strange code, docstrings for functions, website modified if new functionality added).

[github-actions]

Sanitizer Performance Benchmark

Benchmark	main (median)	PR (median)	Change
simple_load_store	0.005s	0.005s	-0.3%
gemm	0.024s	0.024s	+1.0%
gemm_oob	0.024s	0.025s	+2.7%
indirect_load	0.078s	0.078s	+0.7%
nested_loop	0.025s	0.026s	+1.2%
block_pointer_loop_advance	0.007s	0.007s	+0.8%
liger_jsd	0.151s	0.153s	+1.0%
flaggems_layernorm	2.963s	2.986s	+0.8%
Total	3.277s	3.304s	+0.8%

Threshold: >15% regression flagged with ⚠️
Iterations: 1 warmup + 20 measured