Issue title: [Bug] wrong error message for ampersand in function input
 Issue body: ## 🐛 Bug Report

the following seems to emit the wrong error

https://github.com/AleoHQ/leo/blob/d43605538d1fcb225b21c07bb76c1a8708613213/compiler/parser/src/tokenizer/lexer.rs#L222-L228

#### Code snippet to reproduce

```
function main (&self) {}
```

#### Stack trace & error message

```
     Build Starting...
     Build Compiling main program... ("/home/0rphon/Work/Aleo/leo-playground/src/main.leo")
      Done Finished in 0 milliseconds 

Error [EPAR0370021]: Expected more characters to lex but found none.
```

## Expected Behavior
to fall in line with other similar cases it should emit:

```
Error [EPAR0370026]: Could not lex the following content: `&self) {}`.
```

## Your Environment

- testnet3 commit d43605538d1fcb225b21c07bb76c1a8708613213

 Comments: 
 Comment 0: Closed by #1850.
{'source': 'GithubIssues', 'repo_name_with_owner': 'AleoHQ/leo', 'issue_id': 1249988767, 'repo_stars': 314.0}