ui-text multi payload

### Description

Dash v1 ui-text allows for display of multi payloads with the following method:
`{{msg.val1}} : {{msg.val2}}`
ui-text in dash v2 does not.

### Properties

_No response_

### Events

_No response_

### Controls

_No response_

### Existing Examples

Here is v1 ui-text:
And here is v2 ui-text:
Note how v2 shows the inject time stamp on msg.payload.
Seems that v2 only displays msg.payload, no other options or payloads are allowed.
Here is a simple example flow:
`[
{
"id": "4458911c1e76c778",
"type": "inject",
"z": "961fd588498612ec",
"name": "inject",
"props": [
{
"p": "payload"
}
],
"repeat": "",
"crontab": "",
"once": false,
"onceDelay": 0.1,
"topic": "",
"payload": "",
"payloadType": "date",
"x": 240,
"y": 520,
"wires": [
[
"0d54b067a304ff3e"
]
]
},
{
"id": "0d54b067a304ff3e",
"type": "function",
"z": "961fd588498612ec",
"name": "two values",
"func": "msg.val1 = \"hello\";\nmsg.val2 = \"world\";\nreturn msg;",
"outputs": 1,
"timeout": 0,
"noerr": 0,
"initialize": "",
"finalize": "",
"libs": [],
"x": 388.1999816894531,
"y": 521.2000122070312,
"wires": [
[
"16b9638f0febfc0c"
]
]
},
{
"id": "16b9638f0febfc0c",
"type": "ui-text",
"z": "961fd588498612ec",
"group": "4b79c6844003cb20",
"order": 0,
"width": "4",
"height": "1",
"name": "two payload test",
"label": "{{msg.val1}} : {{msg.val2}}",
"format": "{{msg.payload}}",
"layout": "row-left",
"style": false,
"font": "",
"fontSize": 16,
"color": "#717171",
"className": "",
"x": 580,
"y": 520,
"wires": []
},
{
"id": "4b79c6844003cb20",
"type": "ui-group",
"name": "hello world",
"page": "f99789032d3aa38b",
"width": "6",
"height": "1",
"order": -1,
"disp": true,
"className": ""
},
{
"id": "f99789032d3aa38b",
"type": "ui-page",
"name": "Page Stuff",
"ui": "5863c9e6fbc90679",
"path": "/",
"layout": "grid",
"theme": "7e6d1737ae5f9058",
"order": -1,
"className": ""
},
{
"id": "5863c9e6fbc90679",
"type": "ui-base",
"name": "Base Config",
"path": "/dashboard"
},
{
"id": "7e6d1737ae5f9058",
"type": "ui-theme",
"name": "Light",
"colors": {
"surface": "#ffffff",
"primary": "#0094ce",
"bgPage": "#eeeeee",
"groupBg": "#ffffff",
"groupOutline": "#cccccc"
}
}
]`

### Have you provided an initial effort estimate for this issue?

I am no FlowFuse team member