feat: handle national trunk prefix in PhoneNumberTransformer

[janicduplessis]

Description

Phone numbers in countries with a national trunk prefix were mis-formatted when the prefix was typed. PhoneNumberTransformer treated the leading prefix digit as part of the national significant number, so e.g. France 0612345678 rendered as 0 61 23 45 67 (wrong grouping, last digit dropped) instead of 06 12 34 56 78. NANP countries (US/CA) were unaffected — they have no displayed trunk prefix.

Solution

libphonenumber's format patterns describe the national significant number (without the trunk prefix), which is reapplied via a per-format nationalPrefixFormattingRule (e.g. "0$1").

• The generator emits nationalPrefix for a country only when one of its formats has a nationalPrefixFormattingRule — so display-prefix countries (FR/GB/DE/JP/AU/…) get it, while US/CA (prefix "1", no rule) keep bare-number formatting.
• The worklet strips the national prefix before selecting/applying a format, then prepends it back. It re-adds the raw prefix digit (rather than dropping it as E.164 would) so the per-digit cursor mapping stays aligned with the input.

Note: phone-data.ts is regenerated, so the diff also carries a small libphonenumber-js data refresh (it was last generated against older metadata) on top of the nationalPrefix additions.

Test plan

• yarn test — added PhoneNumberTransformer.test.ts cases for FR/GB/JP/AU typed with the leading 0, plus a US case asserting a leading 1 is not treated as a trunk prefix.
• Outputs match libphonenumber-js AsYouType, e.g. FR 0612345678 → 06 12 34 56 78, GB 02012345678 → 020 1234 5678.
• Verified on-device (iOS): the national-only field (includeCallingCode: false) now formats FR/GB correctly as you type.