0029465: Regression relation to 691 version: Extrema_ExtCC returns IsParallel equal to true for not parallel curves

Strengthening of the criteria of the parallel status of the curves by additional checking if the ends of the curves do not diverge.
Test cases for the issue.

tests/lowalgos/extcc/begin

@@ -0,0 +1,12 @@
+proc CheckExtResult {info ref_dist} {
+  global ext_1
+  if {[regexp "ext_1" $info]} {
+    set dist [lindex [length ext_1] end]
+    if { $dist > $ref_dist } {
+      puts "Error: Extrema distance is too big"
+    }
+  } else {
+    puts "Error: Extrema is not found"
+  }
+}
+