Add RemainingDecontaminationTime property

[hayabusa255]

Description

Describe the changes
Added a new static property RemainingDecontaminationTime to calculate the remaining time for the decontamination process.

What is the current behavior? (You can also link to an open issue here)
Currently, there is no easy way to get the remaining time for the decontamination process.

What is the new behavior? (if this is a feature change)
The new RemainingDecontaminationTime property provides an easy way to get the remaining time for the decontamination process.

Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)
No, this PR does not introduce any breaking changes. It adds a new property without modifying existing functionality.

Other information:

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentations

Submission checklist

• I have checked the project can be compiled
• I have tested my changes and it worked as expected

Patches (if there are any changes related to Harmony patches)

• I have checked no IL patching errors in the console

Other

• Still requires more testing

[louis1706]

Is this the real time or the time in game ?

(15sec or 12.5 sec at the start of decontamination)

[hayabusa255]

This property provides the actual remaining decontamination time from the start to the end of the game.