### What changes were proposed in this pull request?
Fix equality comparison of unordered Categoricals.
### Why are the changes needed?
Codes of a Categorical Series are used for Series equality comparison. However, that doesn't apply to unordered Categoricals, where the same value can have different codes in two same categories in a different order.
So we should map codes to value respectively and then compare the equality of value.
### Does this PR introduce _any_ user-facing change?
Yes.
From:
```py
>>> psser1 = ps.Series(pd.Categorical(list("abca")))
>>> psser2 = ps.Series(pd.Categorical(list("bcaa"), categories=list("bca")))
>>> with ps.option_context("compute.ops_on_diff_frames", True):
... (psser1 == psser2).sort_index()
...
0 True
1 True
2 True
3 False
dtype: bool
```
To:
```py
>>> psser1 = ps.Series(pd.Categorical(list("abca")))
>>> psser2 = ps.Series(pd.Categorical(list("bcaa"), categories=list("bca")))
>>> with ps.option_context("compute.ops_on_diff_frames", True):
... (psser1 == psser2).sort_index()
...
0 False
1 False
2 False
3 True
dtype: bool
```
### How was this patch tested?
Unit tests.
Closes#33497 from xinrong-databricks/cat_bug.
Authored-by: Xinrong Meng <xinrong.meng@databricks.com>
Signed-off-by: Takuya UESHIN <ueshin@databricks.com>
(cherry picked from commit 85adc2ff60)
Signed-off-by: Takuya UESHIN <ueshin@databricks.com>
44cfce8548