feat: add MessageFlags.suppress_notifications and flags parameter

[shiftinv]

Summary

Adds MessageFlags.suppress_notifications (discord/discord-api-docs#5910), and implements a flags parameter on all send-like methods.

Checklist

• If code changes were made, then they have been tested
  • I have updated the documentation to reflect the changes
  • I have formatted the code properly by running task lint
  • I have type-checked the code by running task pyright
• This PR fixes an issue
• This PR adds something new (e.g. new method or parameters)
• This PR is a breaking change (e.g. methods or parameters removed/renamed)
• This PR is not a code change (e.g. documentation, README, ...)

[EQUENOS]

(Code review)
Lgtm! Should we deprecate suppress_embeds eventually?

[shiftinv]

Should we deprecate suppress_embeds eventually?

Perhaps, yeah. suppress on Message.edit is already deprecated (was replaced by suppress_embeds), but there's no harm in keeping suppress_embeds for now, in my opinion.

Something I forgot to mention - this PR currently doesn't add a flags parameter to edit methods, just the send methods. Should we add that as well? It would make sense to add them all at once.

[onerandomusername]

Something I forgot to mention - this PR currently doesn't add a flags parameter to edit methods, just the send methods. Should we add that as well? It would make sense to add them all at once.

Yeah, we should add them.

[EQUENOS]

Yeah let's add this parameter to edit methods as well

[shiftinv]

Yeah, we should add them.

Yeah let's add this parameter to edit methods as well

Alrighty, added in c83dfe9.

[EQUENOS]

Lgtm, passed my tests as well.

[onerandomusername]

lgtm