[chore] Global server configuration overhaul (#575)

* move config flag names and usage to config package, rewrite config package to use global Configuration{} struct

Signed-off-by: kim <grufwub@gmail.com>

* improved code comment

Signed-off-by: kim <grufwub@gmail.com>

* linter

Signed-off-by: kim <grufwub@gmail.com>

* fix unmarshaling

Signed-off-by: kim <grufwub@gmail.com>

* remove kim's custom go compiler changes

Signed-off-by: kim <grufwub@gmail.com>

* generate setter and flag-name functions, implement these in codebase

Signed-off-by: kim <grufwub@gmail.com>

* update deps

Signed-off-by: kim <grufwub@gmail.com>

* small change

Signed-off-by: kim <grufwub@gmail.com>

* appease the linter...

Signed-off-by: kim <grufwub@gmail.com>

* move configuration into ConfigState structure, ensure reloading to/from viper settings to keep in sync

Signed-off-by: kim <grufwub@gmail.com>

* lint

Signed-off-by: kim <grufwub@gmail.com>

* update code comments

Signed-off-by: kim <grufwub@gmail.com>

* fix merge issue

Signed-off-by: kim <grufwub@gmail.com>

* fix merge issue

Signed-off-by: kim <grufwub@gmail.com>

* improved version string (removes time + go version)

Signed-off-by: kim <grufwub@gmail.com>

* fix version string build to pass test script + consolidate logic in func

Signed-off-by: kim <grufwub@gmail.com>

* add license text, update config.Defaults comment

Signed-off-by: kim <grufwub@gmail.com>

* add license text to generated config helpers file

Signed-off-by: kim <grufwub@gmail.com>

* defer unlock on config.Set___(), to ensure unlocked on panic

Signed-off-by: kim <grufwub@gmail.com>

* make it more obvious which cmd flags are being attached

Signed-off-by: kim <grufwub@gmail.com>

internal/api/client/status/statuscreate.go

@@ -24,7 +24,6 @@ import (
 	"net/http"
 
 	"github.com/sirupsen/logrus"
-	"github.com/spf13/viper"
 
 	"github.com/gin-gonic/gin"
 	"github.com/superseriousbusiness/gotosocial/internal/api"
@@ -130,12 +129,11 @@ func validateCreateStatus(form *model.AdvancedStatusCreateForm) error {
 		return errors.New("can't post media + poll in same status")
 	}
 
-	keys := config.Keys
-	maxChars := viper.GetInt(keys.StatusesMaxChars)
-	maxMediaFiles := viper.GetInt(keys.StatusesMediaMaxFiles)
-	maxPollOptions := viper.GetInt(keys.StatusesPollMaxOptions)
-	maxPollChars := viper.GetInt(keys.StatusesPollOptionMaxChars)
-	maxCwChars := viper.GetInt(keys.StatusesCWMaxChars)
+	maxChars := config.GetStatusesMaxChars()
+	maxMediaFiles := config.GetStatusesMediaMaxFiles()
+	maxPollOptions := config.GetStatusesPollMaxOptions()
+	maxPollChars := config.GetStatusesPollOptionMaxChars()
+	maxCwChars := config.GetStatusesCWMaxChars()
 
 	// validate status
 	if form.Status != "" {