[bwlogreceiver] FE - Add aliases to log template

[Zeal0us]

It may be worth considering adding the following properties to log_template.json work better with Kibana Infrastructure and feel a bit more seamless:

				"@timestamp": {
					"type": "alias",
					"path": "logtimestamp"
				},
				"host.name": {
					"type": "alias",
					"path": "server"
				},
				"log.file.path": {
					"type": "alias",
					"path": "sourcefilename"
				},

It's very possible more could be mapped to match what you get out of filebeats, but just these certainly make it feel a bit more "out of the box" from what I've experienced so far.