Separated tests into interval and bisection

.gitignore

tests/s1-s2-test-bisection/input/config_test.toml

tests/s1-s2-test-bisection/input/meshes/test_mesh/block.elem

tests/s1-s2-test-bisection/input/meshes/test_mesh/block.lon

tests/s1-s2-test-bisection/input/meshes/test_mesh/block.pts

tests/s1-s2-test-bisection/input/meshes/test_mesh/block.vec

tests/s1-s2-test-bisection/input/meshes/test_mesh/block.vpts

...1-s2-test-bisection/input/meshes/test_mesh/mesher_cmd.txt

tests/s1-s2-test-bisection/input/s1.par

tests/s1-s2-test-bisection/input/s2.par

tests/s1-s2-test-bisection/reference-solution.txt

tests/s1-s2-test-interval/input/config_test.toml

tests/s1-s2-test-interval/input/meshes/test_mesh/block.elem

tests/s1-s2-test-interval/input/meshes/test_mesh/block.lon

tests/s1-s2-test-interval/input/meshes/test_mesh/block.pts

tests/s1-s2-test-interval/input/meshes/test_mesh/block.vec

tests/s1-s2-test-interval/input/meshes/test_mesh/block.vpts

...s1-s2-test-interval/input/meshes/test_mesh/mesher_cmd.txt

tests/s1-s2-test-interval/input/s1.par

tests/s1-s2-test-interval/input/s2.par