[Improvement] Show Trust Lines based on claimed reserve

[WietseWind]

We recently improvd a thing or two in XUMM (home screen) regarding TLs displayed: instead of showing them if present, we show them only if they claim a reserve. It happens that TLs are misconfigured by issuers, so the TLs are fully in default state on the end user side (in XUMM), but because the issuer isn't in default state the TL (ledger object) still exists. It doesn't claim reserve on the user side though.

The best way to determine if it's relevant for the end user is if it claims reserve. Then they opted in to have the TL. Reserve claimed or balance non zero, actually.

I discussed this with XRPscan, Bithomp, etc. and they agree and will change their explorers as well.

The XUMM home screen already respects this, Account Worth should as well :) If not, users see TLs they don't have on their side, and are not claiming reserve. Showing it anyway is only confusing.

This is a sample that uses account_objects and flags to check for the reserve claim, and mocks the output of account_lines.

https://gist.github.com/WietseWind/5df413334385367c548a148de3d8a713