swarm: ctx propagation; bmt fixes; pss generic notification framework (#17150)

* cmd/swarm: minor cli flag text adjustments

* swarm/api/http: sticky footer for swarm landing page using flex

* swarm/api/http: sticky footer for error pages and fix for multiple choices

* cmd/swarm, swarm/storage, swarm: fix  mingw on windows test issues

* cmd/swarm: update description of swarm cmd

* swarm: added network ID test

* cmd/swarm: support for smoke tests on the production swarm cluster

* cmd/swarm/swarm-smoke: simplify cluster logic as per suggestion

* swarm: propagate ctx to internal apis (#754)

* swarm/metrics: collect disk measurements

* swarm/bmt: fix io.Writer interface

  * Write now tolerates arbitrary variable buffers
  * added variable buffer tests
  * Write loop and finalise optimisation
  * refactor / rename
  * add tests for empty input

* swarm/pss: (UPDATE) Generic notifications package (#744)

swarm/pss: Generic package for creating pss notification svcs

* swarm: Adding context to more functions

* swarm/api: change colour of landing page in templates

* swarm/api: change landing page to react to enter keypress

swarm/storage/hasherstore_test.go

@@ -18,6 +18,7 @@ package storage
 
 import (
 	"bytes"
+	"context"
 	"testing"
 
 	"github.com/ethereum/go-ethereum/swarm/storage/encryption"
@@ -60,7 +61,10 @@ func TestHasherStore(t *testing.T) {
 		hasherStore.Close()
 
 		// Wait until chunks are really stored
-		hasherStore.Wait()
+		err = hasherStore.Wait(context.TODO())
+		if err != nil {
+			t.Fatalf("Expected no error got \"%v\"", err)
+		}
 
 		// Get the first chunk
 		retrievedChunkData1, err := hasherStore.Get(key1)