Expanded linting + fix warnings (#1396)

* Expand the linters and types of warnings to improve consistency and safety

* Fail lint workflow if there are errors

* golint has been replaced by revive

* Hand-pick some of the default exclude list

* Ignore error when trying to delete preview gif

* Ignore linter warning opening playlist path

* Rename user field Id -> ID

* A bunch of renames to address linter warnings

* Rename ChatClient -> Client per linter suggestion best practice

* Rename ChatServer -> Server per linter suggestion best practice

* More linter warning fixes

* Add missing comments to all exported functions and properties

core/data/config.go

@@ -516,6 +516,7 @@ func SetVideoCodec(codec string) error {
 	return _datastore.SetString(videoCodecKey, codec)
 }
 
+// GetVideoCodec returns the codec to use for transcoding video.
 func GetVideoCodec() string {
 	codec, err := _datastore.GetString(videoCodecKey)
 	if codec == "" || err != nil {

core/data/messages.go

@@ -6,6 +6,7 @@ import (
 	log "github.com/sirupsen/logrus"
 )
 
+// CreateMessagesTable will create the chat messages table if needed.
 func CreateMessagesTable(db *sql.DB) {
 	createTableSQL := `CREATE TABLE IF NOT EXISTS messages (
 		"id" string NOT NULL,

core/data/migrations.go

@@ -64,7 +64,7 @@ func migrateToSchema1(db *sql.DB) {
 			return
 		}
 
-		var lastUsed *time.Time = nil
+		var lastUsed *time.Time
 		if lastUsedString != nil {
 			lastUsedTime, _ := time.Parse(time.RFC3339, *lastUsedString)
 			lastUsed = &lastUsedTime

core/data/persistence.go

@@ -144,6 +144,7 @@ func (ds *Datastore) Reset() {
 	PopulateDefaults()
 }
 
+// GetDatastore returns the shared instance of the owncast datastore.
 func GetDatastore() *Datastore {
 	return _datastore
 }

core/data/webhooks.go

@@ -169,7 +169,7 @@ func GetWebhooks() ([]models.Webhook, error) { //nolint
 			return webhooks, err
 		}
 
-		var lastUsed *time.Time = nil
+		var lastUsed *time.Time
 		if lastUsedString != nil {
 			lastUsedTime, _ := time.Parse(time.RFC3339, *lastUsedString)
 			lastUsed = &lastUsedTime