fix: Add link to public pages to private NomCom pages

[larseggert]

Fixes #6343

Also fix highlighting of the active tab in the nav tab bar while I'm here, and remove old links that 404. Oh, and force-break some long/bogus UTF8 names.

[larseggert]

I opened #6355 for the spurious CI failure.

[codecov]

Codecov Report

Merging #6345 (8f0a0da) into main (32bb4ef) will decrease coverage by 0.01%.
Report is 37 commits behind head on main.
The diff coverage is 87.83%.

@@            Coverage Diff             @@
##             main    #6345      +/-   ##
==========================================
- Coverage   88.69%   88.68%   -0.01%     
==========================================
  Files         290      290              
  Lines       40390    40420      +30     
==========================================
+ Hits        35823    35846      +23     
- Misses       4567     4574       +7     

Files Changed	Coverage Δ
ietf/celeryapp.py	0.00% <0.00%> (ø)
ietf/help/views.py	63.63% <ø> (+8.46%)	⬆️
ietf/ipr/models.py	88.95% <ø> (ø)
ietf/nomcom/urls.py	100.00% <ø> (ø)
ietf/nomcom/views.py	92.63% <ø> (-0.02%)	⬇️
ietf/urls.py	80.00% <ø> (-0.56%)	⬇️
ietf/ipr/views.py	87.96% <95.45%> (+0.24%)	⬆️
ietf/doc/models.py	88.98% <100.00%> (ø)
ietf/doc/utils.py	87.38% <100.00%> (+0.23%)	⬆️
ietf/doc/views_review.py	95.16% <100.00%> (+0.20%)	⬆️
... and 5 more

... and 2 files with indirect coverage changes

[jennifer-richards]

I'm a little worried about hard-to-maintain template logic, see inline comments. I think probably the best thing would be to replace if selected in "a,b" with if selected == "a" or selected == "b" and leave the logic that computes the selected as it is.

[jennifer-richards]

I think I gave some bad advice - I was looking at creating the template tag I suggested as an alternative to the explosion of "or" clauses in the selected tests and realized that it can be done like

{% if selected in "a,b,c,d,e,f"|split:"," %}

using what we've already got. Sorry for pointing you toward exploding the logic - if you'd like I can clean that up here or in a separate PR.