Chronograf is not applying filter correctly for path tag when using inputs.tail on Windows

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I'm using the Telegraf plugin on Windows to send some messages to InfluxDB.
The messages are getting there but when I use Chronograf to drill through to the value, the filters are not working properly.

Here's a snippet from telegraf.conf :
```
[[inputs.tail]]
files = ["Z:\\telegraf\\test.log"]
from_beginning = false
grok_patterns = ["^.*Error%{GREEDYDATA:msg:string}"]
name_override = "logs"
grok_custom_pattern_files = []
grok_custom_patterns = ''''''
data_format = "grok"
```
So any log message in test.log that has the word "Error" will generate a single field called "msg" with the contents after that.

In Chronograf, I can see the series is created, and if I select *only* the msg value (last column in Chronograf explorer), I can see the values in a table.
However, if I also select the "path" tag (which above has double back-slashes but in Chronograf is represented correctly with single back-slash) then no results are returned.

If I then amend the query directly and change the path name to have double back-slashes, it works.

So looks like when using the explorer view and drilling through metrics, Chronograf should convert a single backslash to double backslash before adding to the query.

Reproduce the issue with the provided inputs.tail configuration on Windows, then inspect the Chronograf explorer drill-through behavior for the path tag. Compare the generated query when the path contains single versus double backslashes; done means selecting the path tag returns the same results as the manually corrected query.

Written by the indexing model from the issue text.