Refactor ID code

[tsmbland]

Description

A few changes to tidy up handling of IDs

• Move id-related code into a new module
• Remove agent_id from AgentSearchSpace
• Remove process_id from ProcessParameter
• Remove the IntoIDMap trait and method as this was only used once

Fixes # (issue)

Type of change

• Bug fix (non-breaking change to fix an issue)
• New feature (non-breaking change to add functionality)
• Refactoring (non-breaking, non-functional change to improve maintainability)
• Optimization (non-breaking change to speed up the code)
• Breaking change (whatever its nature)
• Documentation (improve or add documentation)

Key checklist

• All tests pass: $ cargo test
• The documentation builds and looks OK: $ cargo doc

Further checks

• Code is commented, particularly in hard-to-understand areas
• Tests added that prove fix is effective or that feature works

[codecov]

Codecov Report

Attention: Patch coverage is 86.79245% with 7 lines in your changes missing coverage. Please review.

Project coverage is 95.13%. Comparing base (8876b7b) to head (a2eab40).
Report is 7 commits behind head on main.

Files with missing lines	Patch %	Lines
src/input/agent/search_space.rs	0.00%	2 Missing and 1 partial ⚠️
src/input/process/flow.rs	93.75%	1 Missing and 1 partial ⚠️
src/input/process/parameter.rs	33.33%	0 Missing and 2 partials ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #477      +/-   ##
==========================================
+ Coverage   95.10%   95.13%   +0.02%     
==========================================
  Files          35       36       +1     
  Lines        4947     4931      -16     
  Branches     4947     4931      -16     
==========================================
- Hits         4705     4691      -14     
  Misses        120      120              
+ Partials      122      120       -2     

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[Copilot]

Copilot reviewed 23 out of 23 changed files in this pull request and generated no comments.

[alexdewar]

LGTM! Nice cleanup.

The IntoIDMap trait did have some more users at one point, but it doesn't make sense to keep it around if there's just the one left.

[alexdewar]

It's actually quite common to reuse variable names like this in Rust (it's less dangerous than in e.g. Python) but this is ok too

[tsmbland]

Cool, yeah probably not clear why I did this but was just because later on I use agent_id from search_space_raw because search_space no longer has agent_id. So I just needed to keep seach_space_raw in the namespace. (Equally could have extracted agent_id before converting search_space_raw to search_space)