Use strict comparison in wp-includes/taxonomy.php

[andizer]

Improvement in doing comparisons in taxonomy.php:
Do strict comparison where possible.
Did two small readability improvements.

[SergeyBiryukov]

For some context, we have to be extra careful with this kind of changes, as these values are sometimes an integer and sometimes a numeric string, causing various inconsistencies. See #16101, #22324, #25092, #25852, #43752, #44723 for example.

I've double-checked 47573.diff​ and made some adjustments to ensure the correct types when comparing.

[SergeyBiryukov]

In 45710:

Coding Standards: Use strict comparison in wp-includes/taxonomy.php.

Props andizer, SergeyBiryukov.
Fixes #47573.

[SergeyBiryukov]

Hmm, for some reason the tests pass for me locally, but fail on Travis:
​https://travis-ci.com/WordPress/wordpress-develop/builds/121609760

[SergeyBiryukov]

In 45711:

Taxonomy: Correct some strict comparisons after [45710].

See #47573.