feat: Add channel & message URL formatters

[Jiralite]

Please describe the changes this PR makes and why it should be merged:
Adds channelLink() and messageLink() which formats a link to a channel or message respectively.

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

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Name	Status	Preview	Updated
discord-js	✅ Ready (Inspect)	Visit Preview	Jul 28, 2022 at 6:02PM (UTC)

[almeidx]

These should be re-exported in discord.js and used in the Message#url and Channel#url getters

[codecov]

Codecov Report

Merging #8371 (66debf0) into main (5494791) will increase coverage by 0.09%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #8371      +/-   ##
==========================================
+ Coverage   86.40%   86.49%   +0.09%     
==========================================
  Files          87       87              
  Lines        8221     8278      +57     
  Branches     1098     1104       +6     
==========================================
+ Hits         7103     7160      +57     
  Misses       1075     1075              
  Partials       43       43              

Flag	Coverage Δ
builders	100.00% <100.00%> (ø)
collection	100.00% <ø> (ø)
proxy	73.28% <ø> (ø)
rest	92.53% <ø> (ø)
utilities	100.00% <ø> (ø)
voice	64.08% <ø> (ø)
ws	60.26% <ø> (ø)

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

Impacted Files	Coverage Δ
packages/builders/src/messages/formatters.ts	100.00% <100.00%> (ø)

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[Jiralite]

These should be re-exported in discord.js and used in the Message#url and Channel#url getters

This should be done with c19f6d9.

[Syjalo]

Maybe you will add also for users?
https://discord.com/users/:id
It turns out that this link is valid only for the mobile version. I don't think it should be here.