No operators in feed issue: improve descriptive text

[irees]

[stevevance]

After Ian's redesign it looks like this (without any line breaks):

No Agency in the GTFS Feed had a matching Transitland Operator Agencies in GTFS Feed: : Jet Existing Feed agency_id <-> Transitland Operator associations: : o-9yreb-jet

What I would like to see changed

1. The quantity of agencies in the GTFS feed, printed after "Agencies in GTFS Feed", like this: Agencies in GTFS Feed (1):.
2. Listing the existing feed agency_id <-> Transitland Operator associations with numbers in an ordered list <ol> (not as important).
3. Quoting the agency_id so I can see where it starts and stops (there was once a problem that an agency ID had whitespace at the end of it, but I couldn't see that without opening the agency.txt file).
4. Fewer "why is this space and colon here?" whitespace and colons (although I presume having the line breaks appear will resolve this)
5. A period after "had a matching Transitland Operator".

[stevevance]

The feed fetcher should also count the number of operators that it finds in the feed (each time it fetches) and compare this number to the operatorsInFeed length. If they're different, a feed issue should be created with the same Details as the above feed issue.

This way we can be alerted to potentially new operators in existing feeds.