Simple Upgradable Structures (Cities, Ports, SAMs and Silos) (#1012)

## Description:

https://github.com/openfrontio/OpenFrontIO/issues/776

I've implemented upgradable structures for cities and ports.

As of right now this is just meant as a QOL change for structure
stacking that currently happens and no gameplay changes are intended.

Structure upgrades cost the same as making a new structure of that type
and function the same as making a new structure of that type.

I'm putting up a draft PR for this now since adding support for SAMs and
Silos will take more time to handle the cooldowns and I want to make
sure I'm on the right track for getting this merged.

I also still need to add bot behavior for this and re-enable min
distance for structures.

I didn't see translations for the UnitInfoModal so I've left that out
for now.

I've tested locally in a single player game so far but will document and
test more thoroughly before merging.


![image](https://github.com/user-attachments/assets/321a17cf-26a5-4152-aae1-6b6a691638bb)


![image](https://github.com/user-attachments/assets/8cfdabe6-f0a1-435a-a5a3-05b442427c2f)


## 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 understand that submitting code with bugs that could have been
caught through manual testing blocks releases and new features for all
contributors

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

# Poutine

---------

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

src/core/game/Game.ts

@@ -130,6 +130,7 @@ export interface UnitInfo {
   maxHealth?: number;
   damage?: number;
   constructionDuration?: number;
+  upgradable?: boolean;
 }
 
 export enum UnitType {
@@ -385,8 +386,9 @@ export interface Unit {
 
   // SAMs & Missile Silos
   launch(): void;
-  ticksLeftInCooldown(): Tick | undefined;
+  reloadMissile(): void;
   isInCooldown(): boolean;
+  ticksLeftInCooldown(): Tick | undefined;
 
   // Trade Ships
   setSafeFromPirates(): void; // Only for trade ships
@@ -396,6 +398,10 @@ export interface Unit {
   constructionType(): UnitType | null;
   setConstructionType(type: UnitType): void;
 
+  // Upgradable Structures
+  level(): number;
+  increaseLevel(): void;
+
   // Warships
   setPatrolTile(tile: TileRef): void;
   patrolTile(): TileRef | undefined;
@@ -471,6 +477,7 @@ export interface Player {
     spawnTile: TileRef,
     params: UnitParams<T>,
   ): Unit;
+  upgradeUnit(unit: Unit): void;
 
   captureUnit(unit: Unit): void;