Reference Layer Type Definitions & Cleanup

[knelson-farmbeltnorth]

We currently have these defined Reference Layer types:

OTHER
BACKGROUND_IMAGE
COMMON_LAND_UNIT
ELEVATION_MAP
MANAGEMENT_ZONE
OBSTACLES
PROFIT_MAP
SOIL_TYPE_MAP
VARIETY_LOCATOR

I'm proposing the following renaming and definitions.

"OBSTACLES" is removed to eliminate any confusion whether these are to be passed as ReferenceLayers or in Catalog.FieldBoundaries[n].Obstacles.

OTHER: A type of Reference Layer not otherwise included in this list
IMAGERY: Specific imagery to be used by the data consumer
REFERENCE_BOUNDARIES (see #134)
ELEVATION: Predefined elevation contours to be used by the data consumer
MANAGEMENT_ZONE: Features used or to be used in preparing agronomic recommendations.
PROFIT: Pre-calculated farm profit data to be used by the data consumer
SOIL_TYPE: Features grouping ground sharing common soil taxonomic classification
VARIETY_LOCATOR: Features grouping planted varieties for use in spatial identification during harvest

[knelson-farmbeltnorth]

Changes agreed in the 13 December 2023 meeting with the exception that we need to maintain the Obstacles layer type for obstacles outside of the field. We will document how this should be used vs. the obstacles on the Field Boundaries.