feat(GridFire): major design changes

Switching to an Engine + solver design. Also brought xxHash and Eigen in. Working on QSE and Culling.

subprojects/eigen.wrap

@@ -0,0 +1,13 @@
+[wrap-file]
+directory = eigen-3.4.0
+source_url = https://gitlab.com/libeigen/eigen/-/archive/3.4.0/eigen-3.4.0.tar.bz2
+source_filename = eigen-3.4.0.tar.bz2
+source_hash = b4c198460eba6f28d34894e3a5710998818515104d6e74e5cc331ce31e46e626
+patch_filename = eigen_3.4.0-2_patch.zip
+patch_url = https://wrapdb.mesonbuild.com/v2/eigen_3.4.0-2/get_patch
+patch_hash = cb764fd9fec02d94aaa2ec673d473793c0d05da4f4154c142f76ef923ea68178
+source_fallback_url = https://github.com/mesonbuild/wrapdb/releases/download/eigen_3.4.0-2/eigen-3.4.0.tar.bz2
+wrapdb_version = 3.4.0-2
+
+[provide]
+eigen3 = eigen_dep

subprojects/libcomposition.wrap

@@ -1,4 +1,4 @@
 [wrap-git]
 url = https://github.com/4D-STAR/libcomposition.git
-revision = v1.0.7
+revision = v1.0.9
 depth = 1