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/scouting/www/pipes/cast.ts b/scouting/www/pipes/cast.ts
new file mode 100644
index 0000000..1bb24e8
--- /dev/null
+++ b/scouting/www/pipes/cast.ts
@@ -0,0 +1,15 @@
+import {Pipe, PipeTransform} from '@angular/core';
+
+@Pipe({name: 'cast'})
+export class CastPipe implements PipeTransform {
+  /**
+   * Cast (S: SuperType) into (T: Type) using @Generics.
+   * @param value (S: SuperType) obtained from input type.
+   * @optional @param type (T CastingType)
+   * type?: { new (): T }
+   * type?: new () => T
+   */
+  transform<S, T extends S>(value: S, type?: new () => T): T {
+    return <T>value;
+  }
+}