Address issues in decoding data from the database (vapor#211)

* Retool PostgresDataDecoder not to violate Coding usage invariants, to throw more consistent errors, and to forward its decoding logic consistently.

* Fix tests to clean up connections properly on error, to respect environment overrides for test config, to handle errors sensibly, and to not open lots of pointless extra connections.

* Heavily updates the CI, including fixing some brokenness caused by a GH Actions bug.

Fix passing the logger through on `PostgresConnectionSource` (vapor#203)

Fix `TLSConfiguration.forClient()` deprecation (vapor#209)

Add `PostgresConfiguration.ianaPortNumber` with appropriate value. Us…

…e the property in place of the hardcoded value. (vapor#201)

Use correct minimal dependency of PostgresNIO (vapor#200)

PostgresKit relies on APIs introduced in PostgresNIO 1.4.0 and `Package.swift` now reflects that.

Use PostgresNIO's default JSON coders (vapor#195)

* Use postgres-nio's `_defaultJSONEncoder` and `_defaultJSONDecoder` global variables as the default values for the JSON coders in `PostgresDataEncoder` and `PostgresDataDecoder`

* Deprecate the previous "jsonDecoder" variable of PostgresDataDecoder and rename it to "json"

* Fix spacing slightly in PostgresDataDecoder

* Fix spacing in PostgresDataDecoder

Fix typo in PostgresColumnType.swift (vapor#194)

Set SQLDialect.supportsReturning to true (vapor#189)

Fix force unwrap in PostgresDataDecoder (vapor#184)

* Replace the force unwrap to throws

Things crash in here

* missing return

2.0.0 gm (vapor#182)

* 2.0.0 gm

* file updates

* update guide docs

* fix img

* fix img

* fixes

* fixes

* fixes

* fixes

* fixes

* fixes

* fixes

* fixes

* code cleanup

* add search path

* add searchPath fixes vapor#9

* optional password

* fix decoder force unwrap vapor#175

* pass server hostname, fixes vapor#178

* array type test

* test fluent gm branch

* master + import fix