scouting: Deduplicate action definitions in entry.component.ts

I found it tedious to keep the definitions up-to-date between the .fbs
file and the entry.component.ts file. This patch fixes the issue by
using the generated flatbuffer types everywhere.

I added a helper library to deal with `actionTakenType` properly.
Otherwise the user would have to deal with it manually.

Since Angular templates don't seem to allow manual type casting, I
created a pipe to do it for me.

Signed-off-by: Philipp Schrader <philipp.schrader@gmail.com>
Change-Id: I5f60e2d7b89978f40b5758bb8d04e800d6de230d
diff --git a/WORKSPACE b/WORKSPACE
index a345ff5..f68d1b0 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -918,6 +918,7 @@
         "@//scouting/www/entry:package.json",
         "@//scouting/www/match_list:package.json",
         "@//scouting/www/notes:package.json",
+        "@//scouting/www/pipes:package.json",
         "@//scouting/www/rpc:package.json",
         "@//scouting/www/scan:package.json",
         "@//scouting/www/shift_schedule:package.json",