Implement Cobra CLI tooling, Viper config tooling (#336)

* start pulling out + replacing urfave and config

* replace many many instances of config

* move more stuff => viper

* properly remove urfave

* move some flags to root command

* add testrig commands to root

* alias config file keys

* start adding cli parsing tests

* reorder viper init

* remove config path alias

* fmt

* change config file keys to non-nested

* we're more or less in business now

* tidy up the common func

* go fmt

* get tests passing again

* add note about the cliparsing tests

* reorganize

* update docs with changes

* structure cmd dir better

* rename + move some files around

* fix dangling comma

internal/processing/federation/federation.go

@@ -24,7 +24,6 @@ import (
 	"net/url"
 
 	apimodel "github.com/superseriousbusiness/gotosocial/internal/api/model"
-	"github.com/superseriousbusiness/gotosocial/internal/config"
 	"github.com/superseriousbusiness/gotosocial/internal/db"
 	"github.com/superseriousbusiness/gotosocial/internal/federation"
 	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
@@ -83,7 +82,6 @@ type Processor interface {
 
 type processor struct {
 	db            db.DB
-	config        *config.Config
 	federator     federation.Federator
 	tc            typeutils.TypeConverter
 	filter        visibility.Filter
@@ -91,10 +89,9 @@ type processor struct {
 }
 
 // New returns a new federation processor.
-func New(db db.DB, tc typeutils.TypeConverter, config *config.Config, federator federation.Federator, fromFederator chan messages.FromFederator) Processor {
+func New(db db.DB, tc typeutils.TypeConverter, federator federation.Federator, fromFederator chan messages.FromFederator) Processor {
 	return &processor{
 		db:            db,
-		config:        config,
 		federator:     federator,
 		tc:            tc,
 		filter:        visibility.NewFilter(db),