Plugin hooks (#1452)

* Refactor session and plugin code
* Add context to job tasks
* Show hooks in plugins page
* Refactor session management

pkg/utils/context.go

@@ -0,0 +1,28 @@
+package utils
+
+import (
+	"context"
+	"time"
+)
+
+type valueOnlyContext struct {
+	context.Context
+}
+
+func (valueOnlyContext) Deadline() (deadline time.Time, ok bool) {
+	return
+}
+
+func (valueOnlyContext) Done() <-chan struct{} {
+	return nil
+}
+
+func (valueOnlyContext) Err() error {
+	return nil
+}
+
+func ValueOnlyContext(ctx context.Context) context.Context {
+	return valueOnlyContext{
+		ctx,
+	}
+}