feat(cli): Support displaying storage values in base-2 [#2492] (#2502)

* Update display on repository summary

* Apply throughout app

* Situate units_test

* Update Command Line documentation

* Envar cleanup

* Rename to BytesString

* Restore envar string available for test

* Remove extraneous empty check and restore UIPreferences field for frontend

* PR: config bool cleanup and missed `BaseEnv`s

* Fix lint and test

cli/command_cache_info.go

@@ -73,14 +73,14 @@ func (c *commandCacheInfo) run(ctx context.Context, rep repo.Repository) error {
 
 		maybeLimit := ""
 		if l, ok := path2Limit[ent.Name()]; ok {
-			maybeLimit = fmt.Sprintf(" (limit %v, min sweep age %v)", units.BytesStringBase10(l), path2SweepAgeSeconds[ent.Name()])
+			maybeLimit = fmt.Sprintf(" (limit %v, min sweep age %v)", units.BytesString(l), path2SweepAgeSeconds[ent.Name()])
 		}
 
 		if ent.Name() == "blob-list" {
 			maybeLimit = fmt.Sprintf(" (duration %v)", opts.MaxListCacheDuration.DurationOrDefault(0))
 		}
 
-		c.out.printStdout("%v: %v files %v%v\n", subdir, fileCount, units.BytesStringBase10(totalFileSize), maybeLimit)
+		c.out.printStdout("%v: %v files %v%v\n", subdir, fileCount, units.BytesString(totalFileSize), maybeLimit)
 	}
 
 	c.out.printStderr("To adjust cache sizes use 'kopia cache set'.\n")