[BUG] label key field doesn't support colon as separator

[a110605]

Setup

• Rancher version: v2.8.3
• Rancher UI Extensions:
• Browser type & version: Chrome latest

Describe the bug
The pasted context doesn't support : as separator, but support =
The tooltip said Paste lines of key=value or key: value into any key field for easy bulk entry

To Reproduce

1. Go to Continuous Delivery -> Workspace -> Create
2. Add Labels
3. paste below text in key field

user-firstname: Andy Lee 
user-lastname: aaa
user-id: 123

Result
The text doesn't parse to key and value.

Expected Result
The text should be parsed to key and value.

Screenshots

[gaktive]

We may need to think about this more because : could exist in the key name. There's also the chance that folks could mix = and : together in the same YAML so we'd need better parsing overall (e.g, if no equal signs, assume colon) and then sort out escape characters.

Pushing to 2.10 so we can come up with a strategy.

[richard-cox]

The key name can't have a : (https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/#syntax-and-character-set), though it's not required and it could be in the value (to confirm)