ui: size-field: add more units

This would probably benefit from being an object alá:
```
'GiB': {
    base: 2,
    order: 30,
},
```
but that would be a transparent internal change, and the current way
isn't yet a limitation, so ...

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

www/manager6/form/BandwidthSelector.js

@@ -22,12 +22,15 @@ Ext.define('PVE.form.SizeField', {
     },
 
     units: {
+	'B': 1,
 	'KiB': 1024,
 	'MiB': 1024*1024,
 	'GiB': 1024*1024*1024,
+	'TiB': 1024*1024*1024*1024,
 	'KB': 1000,
 	'MB': 1000*1000,
 	'GB': 1000*1000*1000,
+	'TB': 1000*1000*1000*1000,
     },
 
     // display unit (TODO: make (optionally) selectable)