Improved the nation alliance request logic 🤝 Massive upgrade to singleplayer fun (#2606)

## Response to alliance requests

Previously the way nations responded to alliance requests was quite
simple / boring / exploitable. Basically you couldn't ally them if you
had a bad relation with them, or if you had too many alliances.
Otherwise they would just take it.

Now there is a **complete decision tree which is based on the
difficulty**. The nations should also feel more human now.

For example, just like humans, nations will now consider to take an
alliance even if you have a bad relation with them (If you are a
threat).

Also, nations no longer check if YOU have too many alliances. Now they
do what humans do: Check if THEY have too many alliances (they want to
be able to attack somebody).

Another big change is the default case: Previously it was just `return
true`. Now it's `return isAlliancePartnerSimilarlyStrong`. So they do
what humans do: Take a quick look at their troop count before allying
them.

## Sending alliance requests

Previously alliance requests were sent randomly. Quite boring.

Now we use the same decision tree as for responding.

## Alliance extension requests

They also use the same decision tree.

## Tests

Tested it a lot in singleplayer.
I have planned to add unit tests for all the nation/bot stuff in the
upcoming cleanup phase.

## 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

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

FloPinguin

src/core/execution/BotExecution.ts

@@ -1,6 +1,7 @@
 import { Execution, Game, Player } from "../game/Game";
 import { PseudoRandom } from "../PseudoRandom";
 import { simpleHash } from "../Util";
+import { AllianceExtensionExecution } from "./alliance/AllianceExtensionExecution";
 import { BotBehavior } from "./utils/BotBehavior";
 
 export class BotExecution implements Execution {
@@ -56,11 +57,29 @@ export class BotExecution implements Execution {
       return;
     }
 
-    this.behavior.handleAllianceRequests();
-    this.behavior.handleAllianceExtensionRequests();
+    this.acceptAllAllianceRequests();
     this.maybeAttack();
   }
 
+  private acceptAllAllianceRequests() {
+    // Accept all alliance requests
+    for (const req of this.bot.incomingAllianceRequests()) {
+      req.accept();
+    }
+
+    // Accept all alliance extension requests
+    for (const alliance of this.bot.alliances()) {
+      // Alliance expiration tracked by Events Panel, only human ally can click Request to Renew
+      // Skip if no expiration yet/ ally didn't request extension yet / bot already agreed to extend
+      if (!alliance.onlyOneAgreedToExtend()) continue;
+
+      const human = alliance.other(this.bot);
+      this.mg.addExecution(
+        new AllianceExtensionExecution(this.bot, human.id()),
+      );
+    }
+  }
+
   private maybeAttack() {
     if (this.behavior === null) {
       throw new Error("not initialized");