fix(rtl): keep dial code '+' on the left via LRM

[aradhwan]

Motivation

In RTL locales (e.g., Arabic), the dial code plus sign + can jump to the right side of the digits due to Unicode bidi reordering. Users expect + to remain on the left (e.g., +971).

What this PR changes

• Adds a private _dialCodeLTR getter that wraps dialCode with U+200E (LRM).
• Uses _dialCodeLTR in toString() and toLongString() so display strings render correctly in RTL.
• Leaves the dialCode field untouched (search/filter behavior unchanged).

Rationale

LRM isolates the dial code as LTR, preventing bidi reordering in RTL UI while keeping API and data intact.

Screenshots

Before (LRM)	After (LRM)

Related issue

Fixes #67

Testing

• Verified manually on Android & iOS with locale = ar.
• Confirmed search/filter behavior unchanged (logic still uses raw dialCode).
• Confirmed LTR locales unaffected.

Notes

• Scope limited to directionality.