RawSubFile support multi file access (#173)

This PR is a fix/improvement to a problem that Jonathan had. (#156) The
original implementation opened all subfiles at once witch works for
normal sized datasets but fails at a certain point (thousands of files).

- This solution uses RawSubFile to manage the different file indicies
and only opens the file we need
- Added logger.h from slsDetectorPackage for debug printing (in
production no messages should be visible)

src/RawSubFile.test.cpp

@@ -0,0 +1,76 @@
+#include "aare/RawSubFile.hpp"
+#include "aare/File.hpp"
+#include "aare/NDArray.hpp"
+#include <catch2/catch_test_macros.hpp>
+#include "test_config.hpp"
+
+using namespace aare;
+
+TEST_CASE("Read frames directly from a RawSubFile", "[.files]"){
+    auto fpath_raw = test_data_path() / "raw/jungfrau" / "jungfrau_single_d0_f0_0.raw";
+    REQUIRE(std::filesystem::exists(fpath_raw));
+
+    RawSubFile f(fpath_raw, DetectorType::Jungfrau, 512, 1024, 16);
+    REQUIRE(f.rows() == 512);
+    REQUIRE(f.cols() == 1024);
+    REQUIRE(f.pixels_per_frame() == 512 * 1024);
+    REQUIRE(f.bytes_per_frame() == 512 * 1024 * 2);
+    REQUIRE(f.bytes_per_pixel() == 2);
+
+
+    auto fpath_npy = test_data_path() / "raw/jungfrau" / "jungfrau_single_0.npy";
+    REQUIRE(std::filesystem::exists(fpath_npy));
+
+    //Numpy file with the same data to use as reference
+    File npy(fpath_npy, "r");
+
+    CHECK(f.frames_in_file() == 10);
+    CHECK(npy.total_frames() == 10);
+
+
+    DetectorHeader header{};
+    NDArray<uint16_t, 2> image({static_cast<ssize_t>(f.rows()), static_cast<ssize_t>(f.cols())});
+    for (size_t i = 0; i < 10; ++i) {
+        CHECK(f.tell() == i);
+        f.read_into(image.buffer(), &header);
+        auto npy_frame = npy.read_frame();
+        CHECK((image.view() == npy_frame.view<uint16_t>()));
+    }
+}
+
+TEST_CASE("Read frames directly from a RawSubFile starting at the second file", "[.files]"){
+    // we know this file has 10 frames with frame numbers 1 to 10
+    // f0 1,2,3
+    // f1 4,5,6 <-- starting here
+    // f2 7,8,9
+    // f3 10
+    
+    auto fpath_raw = test_data_path() / "raw/jungfrau" / "jungfrau_single_d0_f1_0.raw";
+    REQUIRE(std::filesystem::exists(fpath_raw));
+
+    RawSubFile f(fpath_raw, DetectorType::Jungfrau, 512, 1024, 16);
+
+
+    auto fpath_npy = test_data_path() / "raw/jungfrau" / "jungfrau_single_0.npy";
+    REQUIRE(std::filesystem::exists(fpath_npy));
+
+    //Numpy file with the same data to use as reference
+    File npy(fpath_npy, "r");
+    npy.seek(3);
+
+    CHECK(f.frames_in_file() == 7);
+    CHECK(npy.total_frames() == 10);
+
+
+    DetectorHeader header{};
+    NDArray<uint16_t, 2> image({static_cast<ssize_t>(f.rows()), static_cast<ssize_t>(f.cols())});
+    for (size_t i = 0; i < 7; ++i) {
+        CHECK(f.tell() == i);
+        f.read_into(image.buffer(), &header);
+        // frame numbers start at 1 frame index at 0 
+        // adding 3 + 1 to verify the frame number
+        CHECK(header.frameNumber == i + 4); 
+        auto npy_frame = npy.read_frame();
+        CHECK((image.view() == npy_frame.view<uint16_t>()));
+    }
+}