Add an option to auto-use default HTTP(S) port for Lavalink

[Drapersniper]

Description of the changes

Users are now allowed to set port to -1 which will automatically set the connection ports to 80/443 depending on the security settings.

Sorry but you cannot test the 443 part of it as it is added on #5593

Have the changes in this PR been tested?

Yes

[Drapersniper]

What to test

Scenario 1:
[p]llset host lavalink.oops.wtf
[p]llset port -1
[p]llset secured # Needs to be set to secured

It should connect successfully

Scenario 2:
[p]llset host lavalink-coders.ml
[p]llset port -1
[p]llset secured # Needs to be set to unsecured

Scenario 3
Repeat Scenario 1 or 2 but have the incorrect [p]llset secured value
It should fail to connect

Scenario 4
Straight after scenario 3 change the secure state [p]llset secure to the correct value.

Scenario 5
[p]llset port docstring should tell users to set the value to -1 to set it to "None"

What to expect

1 - Scenario 1 user is able to connect successfully and play music
2 - Scenario 2 user is able to connect successfully and play music
3 - Scenario 3 connection will fail, it will attempt up to 10 times and then give up, Audio should say "Connection to Lavalink lost"
4 - Audio should tell the user to run [p]audioset restart, after running it user should be able to connect and play music
5 - Docstring is clear and directs the user on how to set the port to None

[Jackenmen]

I think it would have been clearer if, instead of "None", the "Port" field said something like "Default HTTP(S) port".

[Jackenmen]

Thanks!