Polygon areas for presets

Problem/Motivation

Follow-up proposed in comment #10 on #3618910: Expose Surface for use with OpenStreetmap Module et al.. Presets have no way to express a polygon area.

Proposed resolution

Design question, undecided:

• a stored poly mode on the preset,
• an area passed in at run time,
• or both.

Remaining tasks

• Decide the design.
• Postponed until #3614000: Add overpass_api_preset submodule: Provide a Config Entity to save, reuse, and export Overpass queries lands. There is no code for this in MR !9.