feat: use timestamp as message time if exists

[sumo-drosiek]

Instructs Sumo Logic to use timestamp key if it exists. It will ensure that the timestamp extraction is consistent. Auto-detection is fallback, so no behavior change is expected in case timestamp is not added to the log

Checklist

• Changelog updated or skip changelog label added
• Documentation updated
• Template tests added for new features
• Integration tests added or modified for major features

[rnishtala-sumo]

Looks like one of the tests is failing

Diff:
        	            	--- Expected
        	            	+++ Actual
        	            	@@ -9,2 +9,6 @@
        	            	     collector_id = sumologic_collector.collector.id
        	            	+    default_date_formats {
        	            	+      format  = "epoch"
        	            	+      locator = "\"timestamp\":(\\d+)"
        	            	+    }
        	            	 }
        	            	@@ -14,2 +18,6 @@
        	            	     collector_id = sumologic_collector.collector.id
        	            	+    default_date_formats {
        	            	+      format  = "epoch"
        	            	+      locator = "\"timestamp\":(\\d+)"
        	            	+    }
        	            	 }