Enable profiler and profile-guided builds

I used the chance to simplify the Makefile, as this is required for the file check to work correctly. Variables should not contain quotes, as these will be included in the value otherwise.

internal/config/config.go

@@ -123,6 +123,12 @@ type logger struct {
 	Level string
 }
 
+// Profiling configures the usage of a runtime profiler to create optimized binaries.
+type Profiling struct {
+	Enabled bool
+	File    string
+}
+
 // InfluxDB configures the usage of an Influx db monitoring.
 type InfluxDB struct {
 	URL          string
@@ -134,12 +140,13 @@ type InfluxDB struct {
 
 // configuration contains the complete configuration of Poseidon.
 type configuration struct {
-	Server   server
-	Nomad    Nomad
-	AWS      AWS
-	Logger   logger
-	Sentry   sentry.ClientOptions
-	InfluxDB InfluxDB
+	Server    server
+	Nomad     Nomad
+	AWS       AWS
+	Logger    logger
+	Profiling Profiling
+	Sentry    sentry.ClientOptions
+	InfluxDB  InfluxDB
 }
 
 // InitConfig merges configuration options from environment variables and