forc call with `--wallet` parameter bugs

### Description

`forc call` with `--wallet` parameter fails because the wallet has no base assets (0 balance), even for read-only function calls.

### Steps to Reproduce
1. Deploy a minimal Sway contract
2. Run `forc call` without `--wallet` - works
3. Run `forc call` with `--wallet` - fails

### Example Contract
```sway
contract;

abi Demo {
fn get_count() -> u64;
}

impl Demo for Contract {
fn get_count() -> u64 {
5
}
}
```

### Commands
Working command (without wallet - uses default signer - which has funds..):
```bash
forc call --abi ./out/release/demo-abi.json $CONTRACT_ADDRESS get_count
```

Failing command (with wallet):
```bash
forc call --abi ./out/release/demo-abi.json $CONTRACT_ADDRESS get_count --wallet
```

### Error Output
```
thread 'main' panicked at /Users/runner/work/sway/sway/forc-plugins/forc-client/src/op/call/missing_contracts.rs:32:10:
Failed to build transaction: Provider("failed to adjust inputs to cover for missing base asset: failed to get base asset (f8f8b6283d7fa5b672b530cbb84fcccb4ff8dc40f8176ef4544ddb1f1952ad07) inputs with amount: `1`: io error: Response errors; the target cannot be met due to insufficient coins available for f8f8b6283d7fa5b672b530cbb84fcccb4ff8dc40f8176ef4544ddb1f1952ad07. Collected: 0.")
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
```

### Expected behaviour
- The `wallet` parameter should not error/panic in the default dry-run mode - since funds are not required for read-only function calls.
- Error message update: The current error is cryptic. It should clearly state: "Wallet has insufficient funds. Please fund your wallet with base asset ()."
- This is for simulation and/or live-mode - where user funds should be taken into account.