Add loop in the CLI for freezing UTXOs

Prior to this commit the wallet-tool (un)freeze tool would only
allow a single freeze or unfreeze per run. So a user intending
to (un)freeze several UTXOs would have to run the script several
times which would be slow due to the need to sync the wallet
many times.

See also the discussion in: http://gnusha.org/joinmarket/2020-01-09.log

jmclient/jmclient/wallet_utils.py

@@ -980,6 +980,7 @@ def display_utxos_for_disable_choice_default(utxos_enabled, utxos_disabled):
             start += 1
             yield txid, idx
 
+    jmprint("List of UTXOs:")
     ulist = list(output_utxos(utxos_disabled, 'FROZEN'))
     disabled_max = len(ulist) - 1
     ulist.extend(output_utxos(utxos_enabled, 'NOT FROZEN', start=len(ulist)))
@@ -1032,22 +1033,23 @@ def wallet_freezeutxo(wallet, md, display_callback=None, info_callback=None):
     if md is None:
         info_callback("Specify the mixdepth with the -m flag", "error")
         return "Failed"
-    utxos_enabled, utxos_disabled = get_utxos_enabled_disabled(wallet, md)
-    if utxos_disabled == {} and utxos_enabled == {}:
-        info_callback("The mixdepth: " + str(md) + \
-            " contains no utxos to freeze/unfreeze.", "error")
-        return "Failed"
-    display_ret = display_callback(utxos_enabled, utxos_disabled)
-    if display_ret is None:
-        return "OK"
-    (txid, index), disable = display_ret
-    wallet.disable_utxo(txid, index, disable)
-    if disable:
-        info_callback("Utxo: {} is now frozen and unavailable for spending."
-                      .format(fmt_utxo((txid, index))))
-    else:
-        info_callback("Utxo: {} is now unfrozen and available for spending."
-                      .format(fmt_utxo((txid, index))))
+    while True:
+        utxos_enabled, utxos_disabled = get_utxos_enabled_disabled(wallet, md)
+        if utxos_disabled == {} and utxos_enabled == {}:
+            info_callback("The mixdepth: " + str(md) + \
+                " contains no utxos to freeze/unfreeze.", "error")
+            return "Failed"
+        display_ret = display_callback(utxos_enabled, utxos_disabled)
+        if display_ret is None:
+            break
+        (txid, index), disable = display_ret
+        wallet.disable_utxo(txid, index, disable)
+        if disable:
+            info_callback("Utxo: {} is now frozen and unavailable for spending."
+                          .format(fmt_utxo((txid, index))))
+        else:
+            info_callback("Utxo: {} is now unfrozen and available for spending."
+                          .format(fmt_utxo((txid, index))))
     return "Done"
 
 def get_wallet_type():