Split CI build workflows into separate files. Added MPI backend test.

.github/workflows/build-cuda.yml

@@ -0,0 +1,18 @@
+name: Build and Test CUDA Backend
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+  schedule:
+    - cron: '30 8 * * *'
+
+jobs:  
+  build-cuda:
+    runs-on: self-hosted
+    steps:
+    - uses: actions/checkout@v4
+    - name: Run batch file
+      run: cd tests/misc && chmod +x run-crnch-cuda.sh && sbatch run-crnch-cuda.sh
+

.github/workflows/build-mpi.yml

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+name: Build and Test MPI Backend
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+  schedule:
+    - cron: '30 8 * * *'
+
+jobs:  
+  build-and-run-mpi:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+      - uses: awalsh128/cache-apt-pkgs-action@latest #Add OpenMPI to test against 
+        with:
+          packages: openmpi-bin libopenmpi-dev 
+          version: 1.0 
+      - name: Build-MPI
+        run: 
+          cmake -DUSE_MPI=1 -B build_mpi -S . && make -C build_mpi
+      - name: Test-MPI
+        run: make test -C build_mpi
+

.github/workflows/build-serial-omp.yml

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+name: Build and Test Serial and OpenMP backends
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+  schedule:
+    - cron: '30 8 * * *'
+
+jobs:
+  build-and-run-serial:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - name: Build-Serial
+      run: cmake -B build_serial_gnu -S . && make -C build_serial_gnu
+    - name: Test-Serial
+      run: make test -C build_serial_gnu
+
+  build-and-run-omp:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4 
+    - name: Build-OMP
+      run: 
+        cmake -DUSE_OPENMP=1 -B build_omp_gnu -S . && make -C build_omp_gnu
+    - name: Test-OMP
+      run: make test -C build_omp_gnu
+