refactor: more data conversion cleanup

[ClementTsang]

Description

A description of the change, what it does, and why it was made. If relevant (such as any change that modifies the UI), please provide screenshots of the changes:

Another small PR to clean up some data conversion code.

Next PR will probably try to dedupe some Point code since that's a pretty bad waste of memory.

Issue

If applicable, what issue does this address?

Closes: #

Testing

If relevant, please state how this was tested. All changes must be tested to work:

If this is a code change, please also indicate which platforms were tested:

• Windows
• macOS
• Linux

Checklist

If relevant, ensure the following have been met:

• Areas your change affects have been linted using rustfmt (cargo fmt)
• The change has been tested and doesn't appear to cause any unintended breakage
• Documentation has been added/updated if needed (README.md, help menu, doc pages, etc.)
• The pull request passes the provided CI pipeline
• There are no merge conflicts
• If relevant, new tests were added (don't worry too much about coverage)

[codecov]

Codecov Report

Attention: Patch coverage is 26.31579% with 56 lines in your changes missing coverage. Please review.

Project coverage is 41.29%. Comparing base (cd6c60c) to head (493a704).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/data_conversion.rs	0.00%	31 Missing ⚠️
src/data_collection/memory.rs	0.00%	8 Missing ⚠️
src/canvas/widgets/battery_display.rs	75.00%	6 Missing ⚠️
src/app.rs	0.00%	5 Missing ⚠️
src/app/data_farmer.rs	28.57%	5 Missing ⚠️
src/canvas.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##             main    #1653       +/-   ##
===========================================
- Coverage   53.79%   41.29%   -12.51%     
===========================================
  Files         108      109        +1     
  Lines       17893    17885        -8     
===========================================
- Hits         9625     7385     -2240     
- Misses       8268    10500     +2232     

Flag	Coverage Δ
macos-14	37.30% <23.68%> (+0.01%)	⬆️
ubuntu-latest	43.01% <26.31%> (-13.15%)	⬇️
windows-2019	37.22% <24.00%> (+<0.01%)	⬆️

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