Refactor _type_cast & _quote.

[metaskills]

I made a mistake and made _type_cast do quoting too. This is now fixed and we have greatly simplified it along with _quote and we now use these two to cast and quote as needed in our sp_executesql helpers.

Changed sp_executesql_sql_type to have a default String case to nvarchar(max) not ideal and there are places where we prefer the bind contain the proper SQLServer type. For example, uniquness validations yielding a ActiveRecord::Relation::QueryAttribute with a basic cast type vs the in scope cast_type further up.

Added sp_executesql_sql_param which looks out for all SQLServer::Data and quotes it accordingly. For example, date & time objects need single quote '' vs. national N'' quoting.

• New base SQLServer::Data shared for all types. Delegates quoting decisoin back to type.
• Time types use variouse flavors of (Date|Time)#strptime in concert with SQL Server date/time formats in fast string processing.

cc @sgrif

[metaskills]

After this work, I can finally start to attach the ~100 errors in the full ActiveRecord test suite knowing that the type foundation is stronger for us. @sgrif, would love to get your thoughts on that query attribute uniqueness cast value mentioned above at some point.

[metaskills]

Here is an example of a test and the bind attr I get for uniqueness validations. Ideally the cast_type would have been used here vs a basic value so we can understand the true type and do what we need for cast/quoting in sq_executesql.

Topic.validates_uniqueness_of(:title)
topic = Topic.new title: 'abc'
assert topic.valid?

=> #<ActiveRecord::Relation::QueryAttribute:0x007fa11bc34128
 @name="title",
 @original_attribute=nil,
 @type=#<ActiveModel::Type::Value:0x007fa11bc34150 @limit=nil, @precision=nil, @scale=nil>,
 @value="N'abc'",
 @value_before_type_cast="N'abc'",
 @value_for_database="N'abc'">