Closes #339

Still some work to do

* Store type lookup is now case-insensitive
* Fixed NpgsqlTimeTypeMapping to map to TimeSpan, not DateTime

Closes #332

Thanks @lust4life

Closes #327

Scaffolding types with precision/scale works now

Fixes #319

Closes #270

Fixes #286

Fixes #288

This reverts commit dfdc3364.

Pending resolution of
https://github.com/aspnet/EntityFrameworkCore/issues/11077

* Added missing mapping DateTimeOffset -> timestamptz
* Adding literal generation for DateTime

* Multidimensional arrays not yet supported (#314)
* In some cases boxing will occur when comparing (and snapshotting) the
  elements (https://github.com/aspnet/EntityFrameworkCore/issues/11072)

Closes #305

Fixes #313

Closes #306

The functional tests were written for SQL Server and assume that
ORDER BY sorts nulls first, but PostgreSQL sorts nulls last by
default.

Add a context option that makes Npgsql generate NULLS FIRST after
ORDER BY. Since the full feature would also require creating
indexes with nulls first, this is (for now) an internal-only
feature.

Closes #50

For some reason problem surfaced only after switching to Linux...

After store type name change

Adding mappings and literal value generation for the 6 PostgreSQL
built-in range types (int4range, int8range, numrange, tsrange,
tztsrange, daterange).

Note that operation translation (e.g. contains) has not yet been
implemented, only basic mapping.

Closes #63

* Added missing mappings
* Completed literal generation for all mappings and added tests

* Added IdentityAlways and IdentityByDefault as value generation
  strategies alongside Serial. Serial is still the default to
  maintain backwards compatibility.
* Scaffolding is supported
* Migrations are supported, including changing from one identity
  strategy to another (always->default) and from serial to
  identity.