Remote Config Support

[akshat-kumar-singhal]

Background
Gofr support remote log level configuration. This can be extended to allow remote updating other configurations as well.

Proposal
A new interface which can be implemented by any receiver which supports reloading based on configuration at runtime. Remote Config
High level implementation as below:

// structs implementing RemoteConfigurable interface are responsible to update/reload the internal config and make it available in-place, i.e. not require restarting the application
type RemoteConfigurable interface {
  refreshConfig(config map[string]string) error
}

type RemoteConfiguration interface {
  registerReceiver(receiver RemoteConfigurable) bool
  fetchRemoteConfig() error
}

// TODO: this can be moved to a common package as it's used in other places like JWKS fetch as well
// TODO: better name can be given for this interface 
type HTTPGetProvider interface {
   GetWithHeaders(ctx context.Context, path string, queryParams map[string]any,
		headers map[string]string) (*http.Response, error)
}

// GofrRemoteConfig implements RemoteConfiguration interface 
type GofrRemoteConfig struct {
  provider HTTPGetProvider
  receivers RemoteConfigurable
// refreshFrequency configuration
}