chore: remove code nothing uses

Each was checked with git grep across every tracked file (templates, JS,
shell, unit files and the extensionless console daemons) and for
dynamic use (URL names, template names, registries):

- vrtManager: host_is_up, is_kvm_supported, get_emulators,
  get_file_extensions, both get_network_forward, get_snapshots,
  get_storages_images, get_os_type, get_host_arch, the get_pretty_* trio
  and, in util, is_kvm_available, randomMAC, get_max_vcpus, compareMAC,
  pretty_mem, pretty_bytes and validate_uuid; with them the port
  constants only host_is_up read. Some were reached only by their tests,
  which go too.
- The flavor edit page: nothing linked to it; flavors are created and
  deleted on the Flavors page and edited through the API.
- computes.validate_name, UserForm.identity_has_errors, the has_perm
  template tag, the ALLOW_EMPTY_PASSWORD setting nothing reads,
  hidePleaseWaitDialog, default_app_config (ignored since Django 4.1)
  and the Python < 3.6 lines of secret_generator.py.

vrtManager/util.py

@@ -1,6 +1,5 @@
 from django.utils.translation import gettext_noop
 import ipaddress
-import random
 import secrets
 import re
 import string
@@ -8,7 +7,6 @@ import string
 import libvirt
 import lxml.etree as etree
 
-from django.conf import settings
 from django.utils.translation import gettext
 
 
@@ -61,22 +59,6 @@ class HostBusy(ConnectionFailed):
     (HOST_REQUESTS) still wait for its answers."""
 
 
-def is_kvm_available(xml):
-    kvm_domains = get_xml_path(xml, "//domain/@type='kvm'")
-    return kvm_domains > 0
-
-
-def randomMAC():
-    """Generate a random MAC address."""
-    # qemu MAC
-    mac = settings.MAC_OUI + ":%02x:%02x:%02x" % (
-        random.randint(0x00, 0xFF),
-        random.randint(0x00, 0xFF),
-        random.randint(0x00, 0xFF),
-    )
-    return mac
-
-
 def randomUUID():
     """Generate a random UUID."""
     u = [secrets.randbelow(256) for _ in range(16)]
@@ -90,18 +72,6 @@ def randomPasswd(length=12, alphabet=string.ascii_letters + string.digits):
     return "".join([secrets.choice(alphabet) for _ in range(length)])
 
 
-def get_max_vcpus(conn, guest_type=None):
-    """@param conn: libvirt connection to poll for max possible vcpus
-    @param guest_type: optional guest type (kvm, etc.)"""
-    if type is None:
-        guest_type = conn.getType()
-    try:
-        m = conn.getMaxVcpus(guest_type.lower())
-    except libvirt.libvirtError:
-        m = 32
-    return m
-
-
 def xml_escape(xml_str):
     """Replaces chars ' " < > & with xml safe counterparts"""
     if xml_str is None:
@@ -115,26 +85,6 @@ def xml_escape(xml_str):
     return xml_str
 
 
-def compareMAC(p, q):
-    """Compare two MAC addresses"""
-    pa = p.split(":")
-    qa = q.split(":")
-
-    if len(pa) != len(qa):
-        if p > q:
-            return 1
-        else:
-            return -1
-
-    for i in range(len(pa)):
-        n = int(pa[i], 0x10) - int(qa[i], 0x10)
-        if n > 0:
-            return 1
-        elif n < 0:
-            return -1
-    return 0
-
-
 def parse_xml(xml):
     """XML a user entered, read for the panel's checks: its entities not
     expanded, nothing fetched and no DTD; libvirt gets the text itself."""
@@ -181,41 +131,6 @@ def get_xpath(doc, path):
     return result
 
 
-def pretty_mem(val):
-    val = int(val)
-    if val > (10 * 1024 * 1024):
-        return "%2.2f GB" % (val / (1024.0 * 1024.0))
-    else:
-        return "%2.0f MB" % (val / 1024.0)
-
-
-def pretty_bytes(val):
-    val = int(val)
-    if val > (1024 * 1024 * 1024):
-        return "%2.2f GB" % (val / (1024.0 * 1024.0 * 1024.0))
-    else:
-        return "%2.2f MB" % (val / (1024.0 * 1024.0))
-
-
-def validate_uuid(val):
-    if not isinstance(val, str):
-        raise ValueError("UUID must be a string.")
-
-    form = re.match("[a-fA-F0-9]{8}[-]([a-fA-F0-9]{4}[-]){3}[a-fA-F0-9]{12}$", val)
-    if form is None:
-        form = re.match("[a-fA-F0-9]{32}$", val)
-        if form is None:
-            raise ValueError(
-                "UUID must be a 32-digit hexadecimal number. It may take "
-                "the form xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx or may "
-                "omit hyphens altogether."
-            )
-
-        else:  # UUID had no dashes, so add them in
-            val = val[0:8] + "-" + val[8:12] + "-" + val[12:16] + "-" + val[16:20] + "-" + val[20:32]
-    return val
-
-
 def validate_macaddr(val):
     if val is None:
         return