[Help] description formatting

Currently there is a few commands in Core that have backticks in their help description.

This makes it look very convuluted if not using embeds in the help descriptions. Example.
[playlist start embed](https://user-images.githubusercontent.com/1307729/72549621-54a90d80-3891-11ea-894c-f4090586cac9.png)
[playlist start non-embed](https://user-images.githubusercontent.com/1307729/72549625-55da3a80-3891-11ea-8212-7c23cfe660f7.png)
[search embed](https://user-images.githubusercontent.com/1307729/72549698-786c5380-3891-11ea-9124-367732c09ff9.png)
[search non-embed](https://user-images.githubusercontent.com/1307729/72549658-65598380-3891-11ea-99b0-c16eba698bdd.png)

A suggestion that could work would be to strip backticks and all other offending characters when non-embeds. This would also prettify help menu when not using embeds.

Related:
https://github.com/Cog-Creators/Red-DiscordBot/pull/3374/files#r367337558 - Same issue with formatting here.
Draft PR that is related: https://github.com/Cog-Creators/Red-DiscordBot/pull/3379.