Fix remaining errors and enable strict mode (#1628)

## Description:

#1075 

Fixing all remaining type errors caused by strict mode and enable it.

## Please complete the following:

- [x] I have added screenshots for all UI updates
- [x] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [x] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced
- [x] I have read and accepted the CLA agreement (only required once).

## Please put your Discord username so you can be contacted if a bug or
regression is found:

azlod

---------

Co-authored-by: Scott Anderson <662325+scottanderson@users.noreply.github.com>

src/core/execution/FakeHumanExecution.ts

@@ -350,7 +350,7 @@ export class FakeHumanExecution implements Execution {
     const dist = euclDistFN(tile, 25, false);
     let tileValue = targets
       .filter((unit) => dist(this.mg, unit.tile()))
-      .map((unit) => {
+      .map((unit): number => {
         switch (unit.type()) {
           case UnitType.City:
             return 25_000;

src/core/execution/PlayerExecution.ts

@@ -1,7 +1,7 @@
 import { Config } from "../configuration/Config";
 import { Execution, Game, Player, UnitType } from "../game/Game";
 import { GameImpl } from "../game/GameImpl";
-import { TileRef } from "../game/GameMap";
+import { GameMap, TileRef } from "../game/GameMap";
 import { calculateBoundingBox, getMode, inscribed, simpleHash } from "../Util";
 
 export class PlayerExecution implements Execution {
@@ -190,7 +190,11 @@ export class PlayerExecution implements Execution {
     }
 
     const firstTile = cluster.values().next().value;
-    const filter = (_, t: TileRef): boolean =>
+    if (!firstTile) {
+      return;
+    }
+
+    const filter = (_: GameMap, t: TileRef): boolean =>
       this.mg?.ownerID(t) === this.player?.smallID();
     const tiles = this.mg.bfs(firstTile, filter);
 

src/core/execution/SAMLauncherExecution.ts

@@ -1,6 +1,7 @@
 import {
   Execution,
   Game,
+  isUnit,
   MessageType,
   Player,
   Unit,
@@ -80,7 +81,9 @@ class SAMTargetingSystem {
       [UnitType.AtomBomb, UnitType.HydrogenBomb],
       ({ unit }) => {
         return (
-          unit.owner() !== this.player && !this.player.isFriendly(unit.owner())
+          isUnit(unit) &&
+          unit.owner() !== this.player &&
+          !this.player.isFriendly(unit.owner())
         );
       },
     );
@@ -212,6 +215,7 @@ export class SAMLauncherExecution implements Execution {
       this.MIRVWarheadSearchRadius,
       UnitType.MIRVWarhead,
       ({ unit }) => {
+        if (!isUnit(unit)) return false;
         if (unit.owner() === this.player) return false;
         if (this.player.isFriendly(unit.owner())) return false;
         const dst = unit.targetTile();