CLSA-2026-1777542146 vim: Fix of 3 CVEs

CVE-2023-1170: at the end of doput ops.c, clamp the cursor column back to the line length and recompute coladd under virtualedit=all so a Visual block put past the new NUL no longer leaves the cursor pointing past end-of-line. - CVE-2023-1175: in opyank ops.c, when the yank starts inside a...