Load progress percentage sometimes exceeds 100%

[patrickbr]

With #2, the load progress percentage sometimes goes over 100%, both in the terminal output and in the web app. In 7ca1671, I replaced floats with doubles in getLoadStatusPercent(bool total), maybe this already was enough to fix the problem.

Example output:

[2023-10-06 14:45:04.281] INFO : [GEOMCACHE] @ row 1870000000 (100.21%, 219277644 points, 1642377251 (open) polygons)
[2023-10-06 14:45:04.327] INFO : [GEOMCACHE] @ row 1871000000 (100.26%, 219277644 points, 1642377251 (open) polygons)
[2023-10-06 14:45:04.375] INFO : [GEOMCACHE] @ row 1872000000 (100.31%, 219277644 points, 1642377251 (open) polygons)
[2023-10-06 14:45:04.411] INFO : [GEOMCACHE] Received 1872808018 rows
[2023-10-06 14:45:04.411] INFO : [GEOMCACHE] Max QLever id was 2077175600

[patrickbr]

Another thing in noticed in getLoadStatusPercent() which I missed in my initial review of the original PR: a std::atomic<size_t> is created from _curRow here (and also at two other places). I don't think it has the desired effect here, as other threads either still access _curRow directly, or have their own local std::atomic<size_t>. _curRow should be declared as std::atomic<size_t> in GeomCache.h.