feat: use staging RGS server on regtest

[ovitrif]

Closes #337

Description

This PR updates config to use the new staging RGS server on REGTEST.

Preview

regtestRgs.mp4

QA Notes

Test

• new wallet:
• Settings → Advanced → Rappid-Gossip-Sync
• expect text: currently connected to {URL}.

[ovitrif]

cc @piotr-iohk:

1. We should be able to use the test as it was in bitkit RN e2e once this is merged ✅
2. There is no reliable way to validate if the URL is a real RGS server, so I guess that's fine the way it is: it's a setting for techies, who should be aware of the risks…

[Copilot]

Pull Request Overview

This PR configures the application to use a staging RGS (Rapid Gossip Sync) server when running on REGTEST network, addressing issue #337. The change enables testing of RGS functionality in the regtest environment.

Key changes:

• Added staging RGS server URL for REGTEST network configuration
• Improved logging messages for gossip source selection
• Refactored dispatcher creation logic for better reusability

Reviewed Changes

Copilot reviewed 5 out of 5 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
app/src/main/java/to/bitkit/env/Env.kt	Added staging RGS server URL for REGTEST network
app/src/main/java/to/bitkit/services/LightningService.kt	Enhanced logging messages for gossip source configuration
app/src/main/java/to/bitkit/async/ServiceQueue.kt	Extracted dispatcher creation into standalone function
app/src/main/java/to/bitkit/ui/settings/lightning/components/ChannelStatusView.kt	Added suppression for ReturnCount lint warning
app/src/main/java/to/bitkit/ui/screens/wallets/receive/ReceiveConfirmScreen.kt	Removed unused imports

[jvsena42]

Looks good for me, except for the copilot comment

[ovitrif]

Looks good for me, except for the copilot comment

Fixed and force-pushed in 81a7318