fix(MessageManager): throw if delete param is not MessageResolvable

[monbrey]

The MessageManager#delete method could silently resolve without making any API call if the supplied param was not MessageResolvable.

message.channel.messages.delete("755203620831756368") // successfully deletes message
message.channel.messages.delete("1") // throws DiscordAPIError: Unknown Message
message.channel.messages.delete() // would silently resolve
message.channel.messages.delete({ foo: "bar" }) // would silently resolve

This addresses case 3 and 4 above by throwing a TypeError for params which are not MessageResolvable

semver:major

Status

• 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

Semantic versioning classification:

• This PR changes the library's interface (methods or parameters added)
  • This PR includes breaking changes (methods removed or renamed, parameters moved or removed)
• This PR only includes non-code changes, like changes to documentation, README, etc.