feat: add energy, pressure, speed unit convertors

[naveensingh]

Type of change(s)

• Bug fix
• Feature / enhancement
• Infrastructure / tooling (CI, build, deps, tests)
• Documentation

What changed and why

Added converters for energy, pressure, and speed. Constants are mostly from Wikipedia.

Tests performed

• Converting to/from added units

Closes the following issue(s)

• Closes Speed #190
• Closes Pressure #191
• Closes Energy #192

Checklist

• I read the contribution guidelines.
• I manually tested my changes on device/emulator (if applicable).
• I updated the "Unreleased" section in CHANGELOG.md (if applicable).
• I have self-reviewed my pull request (no typos, formatting errors, etc.).
• All checks are passing.