feat: update HeapLang semantics, finishing lang and locations

[markusdemedeiros]

Description

Finish two more files in HeapLang and fix some missing cases in the HeapLang semantics. It also adds in some countable instances, I think that for now it is probably easiest that we just add these to the library. I made an issue to look out for upstreamed Countable classes, we can pivot to those at a later point if they meet our needs.

Checklist

• My code follows the mathlib naming and code style conventions
• I have added my name to the authors section of any appropriate files

Generative AI Guidelines

AI assistance is permitted when making contributions to Iris-Lean, however, generative AI systems tend to produce code which takes a long time to review.
Please carefully review your code to ensure it meets the following standards.

• Your PR should avoid duplicating constructions found in Iris-Lean or in the Lean standard library.
• have statements that do not aid readability or code reuse should be inlined.
• Your proofs should be shortened such that their overall structure is explicable to a human reader. As a goal, aim to express one idea per line.
• In general, proofs should not perform substantially more case splitting than their Rocq counterparts.

In our experience, a good place to begin refactoring is by re-arranging and combining independent tactic invocations.
We also find that pointing generative AI systems to the Mathlib code style guidelines can help them perform some of this refactoring work.