test(frontend): handle new lines (#3977)

# Motivation

Using Svelte v5 #3939 in tests renders the spaces as defined in the
component while in v4 we got just one.

```
- Expected
+ Received

- 0.22 BTC
+ 0.22
+ 		BTC
```

for

```
{formatToken({
			value: balance ?? ZERO,
			unitName: token.decimals,
			displayDecimals: token.decimals
})}
{token.symbol}
```

So we can split the expected results.

src/frontend/src/tests/lib/components/send/SendSource.spec.ts

@@ -20,7 +20,8 @@ describe('SendSource', () => {
 		const balance: HTMLDivElement | null = container.querySelector(balanceSelector);
 
 		expect(source?.textContent).toBe('0xF2777205439a8c7be0425cbb21D8DB7426Df5DE9');
-		expect(balance?.textContent).toBe('0.22 BTC');
+		expect(balance?.textContent).toContain('0.22');
+		expect(balance?.textContent).toContain('BTC');
 	});
 	it('should render all field but balance without value', () => {
 		const { container } = render(SendSource, { ...props, token: undefined });
@@ -38,6 +39,7 @@ describe('SendSource', () => {
 		const balance: HTMLDivElement | null = container.querySelector(balanceSelector);
 
 		expect(source).toBeNull();
-		expect(balance?.textContent).toBe('0.22 BTC');
+		expect(balance?.textContent).toContain('0.22');
+		expect(balance?.textContent).toContain('BTC');
 	});
 });