fix(routing/http/contentrouter): additional FindPeer checks

[aschmahmann]

Noticed a few issues while doing some tracing (e.g. errors not being returned when no data was returned) that caused me to look a little closer here.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 77.77778% with 2 lines in your changes missing coverage. Please review.

Project coverage is 59.79%. Comparing base (d99b7e8) to head (4721a79).

@@            Coverage Diff             @@
##             main     #616      +/-   ##
==========================================
+ Coverage   59.75%   59.79%   +0.03%     
==========================================
  Files         238      238              
  Lines       29979    29984       +5     
==========================================
+ Hits        17914    17928      +14     
+ Misses      10446    10434      -12     
- Partials     1619     1622       +3     

Files	Coverage Δ
routing/http/contentrouter/contentrouter.go	50.56% <77.77%> (+3.74%)	:arrow_up:

... and 8 files with indirect coverage changes