Extract PrimaryKeyQueryable from Queryable

[matthewmcgarvey]

Related to #453

If we want to support database views in the future, one step in getting there is removing the requirement of the database table having a primary key.

When the time comes to allow not setting a primary key, the BaseQueryTemplate not include PrimaryKeyQueryable which will remove any ability to query by the primary key for that model.

[paulcsmith]

Smart! I like this approach

[paulcsmith]

Looks like there are some conflicts. Ping me when you're ready and I'll take another look + merge

[matthewmcgarvey]

@paulcsmith This is ready to be reviewed again. I did tweak it so that PrimaryKeyQueryable does not include Queryable. Seemed like the wrong choice to do that inheritance type structure.

[paulcsmith]

I like this new approach of having them implement just the methods they own and including both modules 👍

Just one thought about removing the abstract def

[jwoertink]

@matthewmcgarvey is there anything else you need to do on this? If not, I think it's ready to merge in.

[matthewmcgarvey]

@jwoertink it's ready, thanks