avoid tag-translating in filter optimizer, fixes crash when filters contains a non-existent tag

[tyrasd]

Description

A oshdb filter goes through some optimization steps for increased performance, e.g. for simple key=value queries, it will use a more efficient code path than for example a filter like key1=value1 or key2=value2. The "fast" path crashed, when a non-existent tag is contained in the filter: The code tries to convert the tag from the OSHDB-internal representation back to strings. This normally works fine, but not for tags which don't exist.

This fixes the bug by replacing the conversion from tag ids to strings by a newly added private method for using tag ids directly for filtering.

This PR also fixes a few minor typos (entitiy -> entity) and refactors some of the osmTag filters slightly (to also use the new helper method and be more similar to each other).

Corresponding issue

Closes GIScience/ohsome-api#154

Checklist

• My code follows the code-style rules, and I have checked on the static analyses and benchmark (if applicable) results
• I have commented my code
• I have written javadoc (required for public methods)
• I have added sufficient unit tests
• I have made corresponding changes to the documentation
• I have updated the CHANGELOG.md
• I have adjusted the examples or created an issue in the corresponding repository
• I have adjusted the benchmark or created an issue in the corresponding repository

[joker234]

So basically, apart from some reformatting and prettyfying the code, the change is to use OSHDBTag and OSHDBTagKey directly instead of translating it to OSMTag or OSMTagKey objects first? This prevents the translator to fail and we can return an empty response?

[tyrasd]

So basically […] the change is to use OSHDBTag and OSHDBTagKey directly instead of translating it to OSMTag or OSMTagKey objects first? This prevents the translator to fail and we can return an empty response?

Exactly.