Update mkYesodWith and refactor so that mkYesod uses the context parser

[jprider63]

Since it looks like you're planning on introducing breaking changes, it seems like a good time for this. This PR is breaking since it updates the type of mkYesodWith to separate the list of contexts from the list of type arguments. This makes mkYesodWith more general since you can now have multiple arguments for contexts. For example:

data Foo a b = Foo a b

class Bar a b where
  ...

mkYesodWith [["Bar", "a", "b"]] "Foo" ["a", "b"] ...

This should generate something like:

instance Bar a b => YesodDispatch (Foo a b) where
    ...

I also updated mkYesod to use the context parser and deprecated mkYesodWith since you should be able to get the same functionality from mkYesod now. Let me know if you don't want to deprecate this.

mkYesodWith was originally introduced in #1055. @Daniel-Diaz, does this look good to you?

This should finish #1365.

After submitting your PR:

• Bumped the version number
• Update the Changelog.md file with a link to your PR
• Check that CI passes (or if it fails, for reasons unrelated to your change, like CI timeouts)

[jprider63]

I've changed the target to better-monads. There aren't any conflicts, but I don't think the tests reran.

[Daniel-Diaz]

@jprider63 I'm OK with more flexibility, but maybe it would be good to have a note on how to migrate current code? Or is that not necessary?

[jprider63]

I doubt it's necessary since this shouldn't impact the majority of users, but I added some more documentation to mkYesod and mkYesodWith. There's also a more detailed example in the cookbook.

It looks like mkYesodSub was removed, so I changed mkYesod's documentation to point to mkYesodSubData and mkYesodSubDispatch instead.

[Daniel-Diaz]

@jprider63 Well, I do use this function, and I would not assume how many people use it. And even a minority deserves a pleasant migration. :) Anyway, thanks for extending the docs! It looks good to me.

[snoyberg]

@Daniel-Diaz Just to confirm: are you OK with this change making it into yesod-core 1.6?

[Daniel-Diaz]

@snoyberg Yes.

[snoyberg]

Cool, thanks!

[jprider63]

Thanks!