Migrate Figure.grdview tests to dvc (GenericMappingTools#1154)

Final round of tests to migrate to DVC for the
`grdview` plotting module. This is related to GenericMappingTools#1131,
and is almost like reverting GenericMappingTools#589 actually.

* Migrate test_grdview baseline images to dvc
* Update fig.grdview baseline images for GMT 6.2.0rc1
* Plot fancy frame for test_grdview_with_perspective
* Update fig.grdview baseline images for GMT 6.2.0rc2
* Use projection="Q15c+" for test_grdview_with_perspective

Author: weiji14

pygmt/tests/baseline/test_grdview_drapegrid_dataarray.png

@@ -0,0 +1,4 @@
+outs:
+- md5: d424deb92bd8cb8846cc43155e4d681b
+  size: 64256
+  path: test_grdview_drapegrid_dataarray.png

pygmt/tests/baseline/test_grdview_drapegrid_dataarray.png.dvc

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+outs:
+- md5: 3d78a0f03717f55ccb18e7e926a82fd9
+  size: 6117
+  path: test_grdview_grid_dataarray.png

pygmt/tests/baseline/test_grdview_grid_dataarray.png

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+outs:
+- md5: 6ec7e9b8e090cf8b239f948c7ba73e0f
+  size: 13701
+  path: test_grdview_grid_file_with_region_subset.png

pygmt/tests/baseline/test_grdview_grid_dataarray.png.dvc

@@ -0,0 +1,4 @@
+outs:
+- md5: df3969a299e8a72711bd71c105bf8536
+  size: 37840
+  path: test_grdview_on_a_plane.png

pygmt/tests/baseline/test_grdview_grid_file_with_region_subset.png

@@ -0,0 +1,4 @@
+outs:
+- md5: 6f644dfa49aa144788ee877c6fd86f37
+  size: 38729
+  path: test_grdview_on_a_plane_styled_with_facadepen.png