%getInitialYPositionsToTryIfDirectionDoesNotMatter Returns the initial y-position
%for a given portBlock when the position can be searched in both directions.
%   yPositionsToTry =
%   getInitialYPositionsToTryIfDirectionDoesNotMatter(portBlock,
%   blockOfGroup, blocksToCheckForIntersection, allBlocksInSystem) returns
%   an initial y-position for the given port block. The function is to be
%   used if portBlock is the only port block in blockOfGroup and no other
%   port blocks have been placed before. In this case the initial
%   y-position is searched in both directions.
