qt: remove leftover empty widget from Asset Info panel (#395)

[JSanchezFDZ]

Problem

The Assets dialog shows an empty box in the bottom-right of the Asset Info
area (most visibly on the Windows Qt build) — issue #395.

Root cause

src/qt/forms/assetsdialog.ui defines a QListWidget named listWidget that
is never populated or referenced from any source file. Its only traces are the
.ui definition and a dead QDialog#AssetsDialog QListWidget#listWidget rule in
general.css. Because it has a fixed minimumSize width of 380px and an
expanding size policy, it reserves space and renders as an empty widget.

Fix

Remove the orphan widget from the .ui and its dead stylesheet rule. Verified
that no code references listWidget (grep across src/qt), and the .ui
remains well-formed XML after the removal.

Closes #395.

[JSanchezFDZ]

Hi @CodeIsTheKey @npq7721 @nandofw — when any of you have a moment (no rush), I'd appreciate a look at a small batch of focused fixes I've opened against develop. Each is one issue / one concern and closes the issue it references:

• qt: remove leftover empty widget from Asset Info panel (#395) #455 (this one) — remove the leftover empty widget in the Asset Info panel (Remove empty table widget on asset info #395, the 25k bounty). Builds clean with --with-gui=qt5 (uic regenerates the .ui fine).
• qt: fix sub-asset creation in non-English locales (#440) #452 — sub-asset creation in non-English locales (GUI - Language - French and others than English - Bug on Sub asset creation #440); same locale-independent index check as the merged Fixed Root asset handling with all languages. #418.
• qt: label asset transactions by type in the history list (#382) #458 — label createasset/mintasset/updateasset in the tx history instead of the generic "Payment to yourself" (Naming asset tx types in the GUI #382).
• rpc: add block timestamp and pagination to getaddressdeltas #453 — add a timestamp field + optional skip/count pagination to getaddressdeltas (closes getaddressdeltas: Missing timestamp information #434 and getaddressdeltas: No limit or pagination support on #433); runtime-tested on regtest with -addressindex.
• wallet: let sendtoaddress skip the optional future argument cleanly (#383) #456 — let sendtoaddress skip the optional future argument cleanly (CLI sendtoaddress Errors with more complicated entries #383); runtime-tested on regtest.
• rpc: persist the latest setgenerate state with ForceSetArg (#448) #454 — complements the already-approved Update mining.cpp #449: switch setgenerate to ForceSetArg so it persists the latest genproclimit (Setgenerate false reponse mentions incorrect number of threads. #448). Touches different lines, so the two are independent.
• rpc: mine to the wallet selected on the setgenerate endpoint (#450) #457 — route setgenerate rewards to the wallet selected on the /wallet/<name> endpoint (Raptoreum Core version v2.0.04.01-unk / OS : Windows / Command / setgenerate #450). Compiles with --enable-wallet; the actual reward routing still needs a miner to confirm, so flagging that explicitly.

All are small and backward-compatible, and I've left ACKs on a few of the open community PRs too. Happy to squash, rebase, or adjust anything. Thanks for maintaining this.