Add 'none' value to the 'dendron.defaultLookupCreateBehavior' setting

[uRohan]

Please select if your request is either something new or an enhancement

• [X] Enhancement of an existing Feature.
• [ ] Request of a new feature.

Please select the area your request applies to. (Multiple selections are Possible. You can leave blank if you're not sure.)

• [ ] Workspace - VSCode workspace, vaults, Intellisense/autocomplete, Dendron settings
• [X] Lookup - Dendron's Lookup Command
• [ ] Views - Dendron Preview, Tree View, Side Panels in the UI
• [ ] Schema - Dendron Schemas
• [ ] Pod - Data import from / export to Dendron
• [ ] Publish - External Site Publish
• [ ] Markdown - Markdown features, such as syntax support and features

Is your feature request related to a problem? Please describe

I keep forgetting to deselect text when creating new notes, so I end up with pieces of text "randomly" appearing in my notes and disappearing from others.

Describe the solution you'd like

It would be nice to have the 'none' option of the 'dendron.defaultLookupCreateBehavior' setting.