Support tailscale certs; handle host case sensitivity variations in debug and routes

[ldemailly]

For *.ts.net use the tailscale client to get the cert(s)

It does pull in a ton of dependencies though, so that makes me hesitate a bit: edit: solved by adding a no_tailscale build tag support

[codecov]

Codecov Report

Attention: Patch coverage is 42.10526% with 11 lines in your changes missing coverage. Please review.

Project coverage is 12.50%. Comparing base (c33371d) to head (902335b).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
proxy_main.go	0.00%	10 Missing ⚠️
rp/reverse_proxy.go	0.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff            @@
##            main     #276      +/-   ##
=========================================
+ Coverage   9.82%   12.50%   +2.67%     
=========================================
  Files          3        4       +1     
  Lines        224      240      +16     
=========================================
+ Hits          22       30       +8     
- Misses       200      208       +8     
  Partials       2        2              

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