fix: fail loudly if extension classes are named the same

[AstreaTSS]

Pull Request Type

• Feature addition
• Bugfix
• Documentation update
• Code refactor
• Tests improvement
• CI/CD pipeline enhancement
• Other: [Replace with a description]

Description

Currently, loading two extensions that have the same class name causes subtle bugs to occur, which eventually culminates in reload_extension and other parts of code to error out in a confusing way (it literally took a whole year of discussion in the help forums to find this, as a refernece). While interactions.py should be able to handle extensions like this, making that work would require breaking changes, so failing loudly is a preferable solution here.

This PR does just that.

Changes

• Error out when initializing an extension if another extension has the same class name.

Related Issues

Test Scenarios

# main.py
bot.load_extension("extension_1")
bot.load_extension("extension_2")
bot.reload_extension("extension_1")

# extension_1.py

from interactions import Extension, slash_command, SlashContext

class MyExtension(Extension):
    @slash_command()
    async def test(ctx: SlashContext):
        await ctx.send("Hello!")

# extension_2.py

from interactions import Extension, slash_command, SlashContext

class MyExtension(Extension):
    @slash_command()
    async def test2(ctx: SlashContext):
        await ctx.send("Hello!")

Python Compatibility

• I've ensured my code works on Python 3.10.x
• I've ensured my code works on Python 3.11.x

Checklist

• I've run the pre-commit code linter over all edited files
• I've tested my changes on supported Python versions
• I've added tests for my code, if applicable
• I've updated / added documentation, where applicable