[processing][saga] Add unit test for point distances alg

(cherry picked from commit 4212dea)

Author: nyalldawson

python/plugins/processing/tests/testdata/expected/saga/point_distances.dbf

@@ -0,0 +1,30 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<SAGA_METADATA>
+  <HISTORY saga-version="2.3.1">
+    <MODULE library="shapes_points" id="3" name="Point Distances">
+      <OPTION type="table_field" id="ID_POINTS" name="Identifier" index="0">fid</OPTION>
+      <OPTION type="choice" id="FORMAT" name="Output Format" index="1">each pair with a single record</OPTION>
+      <OPTION type="double" id="MAX_DIST" name="Maximum Distance">0.000000</OPTION>
+      <INPUT type="shapes" id="POINTS" name="Points">
+        <FILE>/home/nyall/dev/QGIS/python/plugins/processing/tests/testdata/custom/points.shp</FILE>
+      </INPUT>
+      <OUTPUT type="table" id="DISTANCES" name="Distances">Distances [points]</OUTPUT>
+    </MODULE>
+  </HISTORY>
+  <SOURCE>
+    <FILE>/home/nyall/dev/QGIS/python/plugins/processing/tests/testdata/expected/saga/point_distances.dbf</FILE>
+    <DATABASE>
+      <FIELDS>
+        <FIELD TYPE="STRING">ID_POINT</FIELD>
+        <FIELD TYPE="STRING">ID_NEAR</FIELD>
+        <FIELD TYPE="DOUBLE">DISTANCE</FIELD>
+      </FIELDS>
+    </DATABASE>
+    <PROJECTION>
+      <OGC_WKT>GEOGCS["GCS_WGS_1984",DATUM["D_WGS_1984",SPHEROID["WGS_1984",6378137,298.257223563]],PRIMEM["Greenwich",0],UNIT["Degree",0.017453292519943295]]</OGC_WKT>
+      <PROJ4>+proj=longlat +a=6378137.000000 +b=6356752.314245 +no_defs</PROJ4>
+      <EPSG>-1</EPSG>
+    </PROJECTION>
+  </SOURCE>
+  <DESCRIPTION></DESCRIPTION>
+</SAGA_METADATA>

python/plugins/processing/tests/testdata/expected/saga/point_distances.mtab

@@ -0,0 +1 @@
+GEOGCS["WGS 84",DATUM["WGS_1984",SPHEROID["WGS 84",6378137,298.257223563,AUTHORITY["EPSG","7030"]],AUTHORITY["EPSG","6326"]],PRIMEM["Greenwich",0,AUTHORITY["EPSG","8901"]],UNIT["degree",0.0174532925199433,AUTHORITY["EPSG","9122"]],AUTHORITY["EPSG","4326"]]

python/plugins/processing/tests/testdata/expected/saga/point_distances.prj

@@ -486,3 +486,17 @@ tests:
         hash: 6f81c858fc7575eaff6258b6e75bf4427d0568d5134837523b730929
         type: rasterhash
 
+  - algorithm: saga:pointdistances
+    name: Point distances
+    params:
+      FORMAT: 1
+      ID_POINTS: fid
+      MAX_DIST: 0.0
+      POINTS:
+        name: custom/points.shp
+        type: vector
+    results:
+      DISTANCES:
+        name: expected/saga/point_distances.dbf
+        type: vector
+