fix: Throw error on no message id for Message#fetchReference()

[Jiralite]

Please describe the changes this PR makes and why it should be merged:
Resolves #10294.

Simply put: if there's no message id, throw ErrorCodes.MessageReferenceMissing.

Also, the JSDoc had these properties as ?. ? does not indicate undefined—it indicates <type> | null.¹

Status and versioning classification:

• Code changes have been tested against the Discord API, or there are no code changes
• I know how to update typings and have done so, or typings don't need updating

Footnotes

1. https://jsdoc.app/tags-type ↩

[vercel]

The latest updates on your projects. Learn more about Vercel for Git ↗︎

Name	Status	Preview	Comments	Updated (UTC)
discord-js	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	May 24, 2024 1:07pm
discord-js-guide	✅ Ready (Inspect)	Visit Preview	💬 Add feedback	May 24, 2024 1:07pm

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 1.83%. Comparing base (27d0659) to head (2f315b0).

Additional details and impacted files

@@            Coverage Diff            @@
##            main   #10295      +/-   ##
=========================================
+ Coverage   1.42%    1.83%   +0.41%     
=========================================
  Files         64      117      +53     
  Lines       3238     4912    +1674     
  Branches      64       71       +7     
=========================================
+ Hits          46       90      +44     
- Misses      3192     4822    +1630     

Flag	Coverage Δ
brokers	1.83% <ø> (+0.41%)	⬆️
builders	1.83% <ø> (+0.41%)	⬆️
collection	1.83% <ø> (+0.41%)	⬆️
discord.js	1.83% <ø> (+0.41%)	⬆️
formatters	1.83% <ø> (+0.41%)	⬆️
guide	1.83% <ø> (+0.41%)	⬆️
next	1.83% <ø> (+0.41%)	⬆️
proxy	1.83% <ø> (+0.41%)	⬆️
rest	1.83% <ø> (+0.41%)	⬆️
util	1.83% <ø> (+0.41%)	⬆️
utilities	1.83% <ø> (+0.41%)	⬆️
voice	1.83% <ø> (+0.41%)	⬆️
website	1.83% <ø> (+0.41%)	⬆️
ws	1.83% <ø> (+0.41%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Sentry.
📢 Have feedback on the report? Share it here.