feat: Implement IPickupEvent to ExplodingGrenadeEventArgs and ChangedIntoGrenadeEventArgs

[warquys]

Implement IPickupEvent to ExplodingGrenadeEventArgs and ChangedIntoGrenadeEventArgs.

Description

Describe the changes
Explicit Interface Implementation of IPickupEvent to ExplodingGrenadeEventArgs and ChangedIntoGrenadeEventArgs.

What is the current behavior? (You can also link to an open issue here)
ExplodingGrenadeEventArgs and ChangedIntoGrenadeEventArgs are not an IPickupEvent..

What is the new behavior? (if this is a feature change)
ExplodingGrenadeEventArgs and ChangedIntoGrenadeEventArgs are now an IPickupEvent..

Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)
No.

Other information:
Sugestion of banalnybanan: https://discord.com/channels/656673194693885975/663978314683252777/1337846404013490216

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

I do not have an SCP sl server, can some one test it for me :)

[VALERA771]

Okay why we need to make explicit properties here? Yeah it seems pretty useless but we made it in other events so I think that we need to follow current style

[louis1706]

Okay why we need to make explicit properties here? Yeah it seems pretty useless but we made it in other events so I think that we need to follow current style

i agree on the following current style (i only accept for the file that would need breaking change to make it use IPickupEvent)