Scan the complete cross-section for the geometry table of a lasym run

[CharlesCNorton]

Fixes #777.

The cross-section table (ygeo, yinden, yellip, ytrian, yshift) scanned theta in [0, pi] at the plane zeta and then the reflected plane 2 pi - zeta with Z -> -Z, which reconstructs the other half of the contour only under stellarator symmetry. A lasym run stores the complete contour, so it is now scanned in a single pass over all nThetaEff points at the plane itself; the symmetric run keeps its two passes.

Checked on cth_like_fixed_bdy in both symmetry modes: all five columns agree between the two runs to 1e-14. On cth_like_fixed_bdy_asym the boundary ellipticity moves from 2.03788 to 2.06080 in the zeta = 0 plane and from 0.71460 to 0.73748 in the zeta = pi/nfp plane; educational_VMEC with the same change (jonathanschilling/educational_VMEC#20) prints the same two values.