Fixes#10926
Contains the following changes:
- Adds a new ERC_SCH_PIN_CONTEXT class which is used to provide deterministic
comparison between items causing ERC violations (e.g. pins) when associated
with a SCH_SHEET_PATH context.
- Adds association of SCH_SHEET_PATHs for ERC_ITEMs and the sub-schematic items
which caused an ERC violation. This allows correct display of markers on the
sheets of interest only, and allows correct naming resolution and cross-probing
from the ERC dialog.
- Adds a new ERC_TREE_MODEL class, derived from RC_TREE_MODEL, which correctly
resolves component references across heirarchical sheets using the associated
SCH_SHEET_PATHs. This allows sheet-specific component references to be displayed
correctly in the ERC results tree.
- Updates SCH_MARKER to only draw sheet-specific markers on the sheet causing
an ERC violation.
- Increments the schematic file version.
- When loading a schematic with legacy ERC exclusions, discards those of type
ERCE_PIN_TO_PIN_WARNING, ERCE_PIN_TO_PIN_ERROR, ERCE_HIERACHICAL_LABEL, and
ERCE_DIFFERENT_UNIT_NET as there is no safe way to automatically infer the
information which is now stored with these exclusions (sheet paths for error
location and related items). Requiring users to (once) re-add exclusions is
preferable to silently incorrectly matching new ERC issues to legacy exclusions.
All labels need to be attached to a net that has at least 2 pins in
order for this to be a valid net. To check for the existing pins, we
need to interate over all subgraphs in the net, counting pins