Metadata and image resolution write test

The goal of MR is to control the correct saving of metadata and resolution in plugins that support them.

- Modified the basic write test to verify that resolution and metadata are saved correctly.
- Verifies the correct functioning of MicroExif in plugins that use it to save metadata.
- EXR: fixed wrong vertical resolution (error found with this MR).
- Added EXR, JXR, JXL, PCX metadata test.

autotests/write/basic/pcx.json

@@ -0,0 +1,7 @@
+{
+    "format" : "pcx",
+    "resolution" : {
+        "dotsPerMeterX" : 10000,
+        "dotsPerMeterY" : 20000
+    }
+}