Replace numeric degrees with symbolic label:

Due to rounding errors when converting to niceAngles,
the numeric value displayed can lead to invalid
triangles. i.e. an SSA triangle with side, side, angle
values that produces a triangle that does not exist.

This change is to just replace the numeric rounded value
displayed with a theta character to show that the angles
are equal and that the bisector theorem can be used.
Skip try-catch in ?debug mode

Test Plan:
Saw an exception in the network panel!

Auditors: eater
Merge pull request #44904 from awmorgan/master

angle-bisector-theorem: replace numeric with symbolic angle
Add in some missing wpluralization words and fix an issue with cardinal() pluralizing when it should've been singular.
Brainfart, jumping jack already existed.
Fix issue with congruent_triangles_2 not showing x

fix #45164; fix #45163; fix #45162; fix #45155; fix #45143; fix #45142;
fix #45141; fix #45140; fix #45134; fix #45125; fix #45105; fix #45101;
fix #45098; fix #45094; fix #45087; fix #45082; fix #45076; fix #45065;
fix #45057; fix #45044; fix #45034; fix #44966; fix #44928; fix #44817;
fix #36534; fix #32123

Test plan: http://localhost:8000/exercises/congruent_triangles_2.html?seed=62&problem=parr&debug note that "x" is shown.
Fix the last place we're using %s in $._() messages.

Auditor: john

Test plan:
Fingers crossed
Oops, missed one place with %s in this file... :-(

Auditor: john
Merge branch 'master' of github.com:Khan/khan-exercises
Merge branch 'master' into i18n