eoc: replace u_set_hp with math

[andrei8l]

Summary

None

Purpose of change

Continue migrating things to math

• Alternative to: Fix #70813 #70814
• Closes: u_set_hp with target_part as a variable object is wrong. #70813 (invalidates)

Describe the solution

1. Replace "u_set_hp" with math's u_hp()
2. Add ALL_MAJOR and ALL_MINOR special values to u_hp() to emulate "major_only" and "minor_only"
3. Make widget clauses set a context variable and use math's u_hp() there too
4. Delete "u_val": "hp"

Describe alternatives you've considered

N/A

Testing

Loaded a test with all mods.
Widget tests still pass.

Additional context

@GuardianDll can you double check the JSON please. In particular, there are some odd cases where all hp is set to 999 then individually to X that I might have misunderstood.

The old increase_only can be replaced with max( u_hp(...), ...) but that doesn't work well with ALL/ALL_MAJOR/ALL_MINOR. It

[github-actions]

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[GuardianDll]

odd cases where all hp is set to 999 then individually to X that I might have misunderstood

iirc it's because, for some reason, when you die, even if prevent death event worked as expected, hp of all sublimbs goes to 0, and it can't be healed
don't know is it still a problem, someone need to test it in the future

[andrei8l]

Thanks for merging