Make connection param mandatory when literal conn str used at design time

[dmitry-a-morozov]

At the moment there are 2 ctors on generated command types:

1. connection: string * ?commandTimeout: int -> 'Command.
2. ?connection: SqlConnection * ?transaction: SqlTransaction * ?commandTimeout: int -> 'Command.

The fact that all parameters are optional for the second constructor allows to create instance of command without providing any parameters. In that case connection string provided at design time reused at run-time. This makes sense for config file based configuration e.g.

type Get42 = <"SELECT 42", "name=AdventureWorks">

But can lead to unintended mistakes when literal used at design time

type Get42 = <"SELECT 42", "Server=.;Database=AdventureWorks;Trusted_Connection=yes">

So proposal is to make connection instance mandatory parameter in second ctor if connection string literal provided at design time. Type signature of second ctor should be :
`connection: SqlConnection * ?transaction: SqlTransaction * ?commandTimeout: int ->

Based on feedback from @dsevastianov.

[dmitry-a-morozov]

Fixed in v1.8.2