[V3] setURL bug fix

[atterpac]

Description

Changes setURL implementation to use the assetServer GetStartURL

Fixes # (issue)
SPA style routing from backend to window.SetUrl("/#/about")

Type of change

Please delete options that are not relevant.

• [ X ] Bug fix (non-breaking change which fixes an issue)

Doctor

# System
| Name         | Ubuntu                             |
| Version      | 22.04                              |
| ID           | ubuntu                             |
| Branding     | 22.04.3 LTS (Jammy Jellyfish)      |
| Platform     | linux                              |
| Architecture | amd64                              |
| CPU          | AMD Ryzen 7 3700X 8-Core Processor |
| GPU 1        | Unknown                            |
| Memory       | 24GB                               |

# Build Environment
| Wails CLI    | v3.0.0-alpha.4                           |
| Go Version   | go1.22.4                                 |
| Revision     | ab06920e74473cb0e34bf2dfffdd8bda023f3ddc |
| Modified     | true                                     |
| -buildmode   | exe                                      |
| -compiler    | gc                                       |
| CGO_CFLAGS   |                                          |
| CGO_CPPFLAGS |                                          |
| CGO_CXXFLAGS |                                          |
| CGO_ENABLED  | 1                                        |
| CGO_LDFLAGS  |                                          |
| GOAMD64      | v1                                       |
| GOARCH       | amd64                                    |
| GOOS         | linux                                    |
| vcs          | git                                      |
| vcs.modified | true                                     |
| vcs.revision | ab06920e74473cb0e34bf2dfffdd8bda023f3ddc |
| vcs.time     | 2024-06-08T22:28:38Z                     |


# Dependencies
| gcc        | 12.9ubuntu3                                                |
| gtk3       | not installed. Install with: sudo apt install libgtk-3-dev |
| npm        | 10.5.0                                                     |
| pkg-config | 0.29.2-1ubuntu3                                            |
| webkit2gtk | 2.44.2-0ubuntu0.22.04.1                                    |