Provide constants in non-Latin scripts (Cyrillic, Greek, Arabic, Hebrew) #269

The parsing machinery is fully Unicode-clean — \w, .lower(), and the piece logic all handle non-Latin scripts — but the constant sets (titles, prefixes, conjunctions, suffixes) are almost entirely Latin-script. Verified on v1.3.0 that runtime additions work end-to-end with no code changes, e.g.:

>>> C = Constants()
>>> C.titles.add('г-н')
>>> C.prefixes.add('بن')
>>> HumanName("г-н Иван Петров", constants=C).title
'г-н'
>>> HumanName("محمد بن سلمان", constants=C).last
'بن سلمان'

Unlike Latin transliterations (which collide across cultures and need opt-in flags), native-script constants cannot collide with Latin-script names, so they are viable as defaults. Only within-script ambiguity needs vetting.

Candidates:

• Cyrillic titles: г-н, г-жа, д-р, проф, акад; Ukrainian пан, пані. (Abbreviated forms like проф. currently work only by accident via the leading-position period_abbreviation fallback; hyphenated г-н doesn't.)
• Cyrillic conjunctions: и; Ukrainian і/та (interacts with the initial-regex question, see Should a bare 'И' parse as an initial or the conjunction 'and'? (e.g. 'Хосе И Мария Сантос') #267)
• Cyrillic suffixes: мл/ст (junior/senior) — needs within-script collision vetting
• Greek: titles κ, κα, κος, δρ, καθ; conjunction και
• Arabic script prefixes: بن (bin), بنت (bint), ابن (ibn), أبو/ابو (abu), آل (Āl); title الشيخ. Excluded: standalone ال (normally attached, too ambiguous), conjunction و (attaches without a space)
• Hebrew prefixes: בן (ben), בת (bat); title מר. Titles containing geresh/gershayim (ד"ר, גב') need testing against the nickname-extraction regexes first.

Out of scope: CJK (family-first order and unspaced segmentation — see #83), Cyrillic patronymic suffixes (already covered by the 1.3.0 regexes).

Coverage should be parsing-behavior tests per script, not assertions on set contents. Related: #265, #266.