Add road height field with unit dropdowns

[1ec5]

Implemented the roadheight field type based on the roadspeed field type. The new field has an explicit option to choose the unit of measurement (between meters and feet). When the field is set to feet, an additional input box lights up to allow the user to enter inches separately.

Initial state in Vietnam:

maxheight=4.8:

Initial state in the U.S.:

maxheight=12':

maxheight=12'6":

maxheight=36":

maxheight=below_default:

Multiple selection:

Fixes #3614. Depends on rapideditor/country-coder#30.

[1ec5]

This placeholder could probably be restored, but rewritten so that it only encourages the use of . as a decimal separator but doesn’t encourage putting ' and " directly in the field.

[1ec5]

These abbreviations are already present in the YAML file, but only as part of format strings:

iD/data/core.yaml

Line 2278 in bb56584

feet: "{quantity} ft"

In theory, we could reuse those strings to decide whether to display the unit dropdown to the left or right of the input box, but I don’t know if any language needs that extra complexity.

[1ec5]

Regarding #7129 (comment), I think we could generalize this field to cover the other length fields (Height, Length, Width, and Elevation). However, if we ever add fields for attraction:minheight and attraction:maxheight, they’ll need a separate custom field because some countries measure human heights with different units than vehicle or building heights.

[1ec5]

The new maxheight field type would be useful for openstreetmap/id-tagging-schema#232 as well.