feat(comp): Add descriptions for revision comp

Ref: HIP 0008

When completing a revision, extra information will be shown for
shells that support completions (fish, zsh).  For example:

$ helm get manifest nginx --revision <TAB>
1  -- App: 1.19.1, Chart: nginx-6.0.2
2  -- App: v0.34.1, Chart: nginx-ingress-1.41.2

Signed-off-by: Marc Khouzam <marc.khouzam@montreal.ca>

cmd/helm/history.go

@@ -193,7 +193,9 @@ func compListRevisions(toComplete string, cfg *action.Configuration, releaseName
 		for _, release := range hist {
 			version := strconv.Itoa(release.Version)
 			if strings.HasPrefix(version, toComplete) {
-				revisions = append(revisions, version)
+				appVersion := fmt.Sprintf("App: %s", release.Chart.Metadata.AppVersion)
+				chartDesc := fmt.Sprintf("Chart: %s-%s", release.Chart.Metadata.Name, release.Chart.Metadata.Version)
+				revisions = append(revisions, fmt.Sprintf("%s\t%s, %s", version, appVersion, chartDesc))
 			}
 		}
 		return revisions, cobra.ShellCompDirectiveNoFileComp

cmd/helm/testdata/output/revision-comp.txt

@@ -1,6 +1,6 @@
-8
-9
-10
-11
+8	App: 1.0, Chart: foo-0.1.0-beta.1
+9	App: 1.0, Chart: foo-0.1.0-beta.1
+10	App: 1.0, Chart: foo-0.1.0-beta.1
+11	App: 1.0, Chart: foo-0.1.0-beta.1
 :4
 Completion ended with directive: ShellCompDirectiveNoFileComp