Floating point uses float instead of double

[gmarz]

We need to ensure AutoMap() also adheres to this.

https://www.elastic.co/guide/en/elasticsearch/reference/master/breaking_50_mapping_changes.html#_floating_points_use_literal_float_literal_instead_of_literal_double_literal

Should this be considered breaking?

[russcam]

It's breaking because the default mapping for a number type is now float and no longer double, so going from double precision floating point to single precision floating point. This breaks the default NumberType for the NumberAttribute, NumberProperty and also the ContentLengthField on AttachmentProperty (which uses NumberProperty).

I think we're OK with auto mapping generally because if you specify a property as type double, mapping inference will map it as a double, and likewise for float; if you specify float, it'll be mapped as a float.

Overriding auto mapping using .Properties() is also a breaking change.