Unicode IVS handling

[miurahr]

Describe the bug
When converting strings with IVS: Ideograph Variation Selector, unihandecode does not convert correctly.

Related issue
(if exist)

To Reproduce
A following test become failure.

def test_ivs():
    s1 =  "\U0000845B\U000E0100飾区"
    s2  = "\U0000845B\U000E0101城"
    u = unihandecode.Unihandecoder('ja')
    r1 = u.decode(s1)
    r2 = u.decode(s2)
    assert r1.startswith('katsu')
    assert r2.startswith('katsura')
    assert r1 == 'katsushika ku'
    assert r2 == 'katsuragi'

\U0000845B\U000E0100飾区 is a variation of 葛飾区 and \U0000845B\U000E0101城 is a variation of 葛城 which is used in location name 葛城市

Expected behavior

Test passed.

Environment (please complete the following information):
master head: 40b419d839a028348427fc0eab959f64119a32c0

[miurahr]

In unicode standard chart, these are defined as

[miurahr]

r1 become AssertionError: assert 'Katsushikaku Ku' == 'Katsushikaku'

[github-actions]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 5 days

[github-actions]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 5 days

[miurahr]

The case should be handled with https://github.com/miurahr/pykakasi

[github-actions]

This issue is stale because it has been open 30 days with no activity. Remove stale label or comment or this will be closed in 5 days