Set default for Drawing Order of Object Layers.

AsIs
When creating a new Object layer, the default value for Drawing Order is "Top Down".

Describe the solution you'd like
For our game we only need "Manual". As Level Designers are often creating new Object layers, this gets overseen quite some times. It feels like a such basic decision for the project on how Object layers are treated, that I wish that this can be set one time and then is the default for all new Object layers created.

(Alternative) possible solutions I could think of:

1. Make a new option in the preferences, like "Default Drawing Order for Object Layers".
2. When creating a new Map, it would feel natural to decide there with Map Properties which default value should be offered when creating new Object layers:
   
3. Maybe some .ini setting I could take care of for my map or project? So it's chosen for all my Object Layers "Manual" by default?

Looking forward to your thoughts! :)

No files, tests, or entry points are named in the issue. Start by tracing where new Object layers receive their Drawing Order and compare the proposed preferences, map properties, and .ini configuration approaches; done means a decided configuration path reliably defaults new Object layers to the selected value.