### Summary

When adding content to a file using `blockinfile`, it is hard to prepend/append a blank line to the block.

e.g. this would be the result when using EOF:
````ini
# network settings
foo = bar
baz = qux
# BEGIN ANSIBLE MANAGED BLOCK
something = 123
# END ANSIBLE MANAGED BLOCK
````

That's hard to use. This would be better (and conventional):
````ini
# network settings
foo = bar
baz = qux

# BEGIN ANSIBLE MANAGED BLOCK
something = 123
# END ANSIBLE MANAGED BLOCK
````

That blank space is so important. Without it the file becomes unreadable, especially when there are multiple blocks, or the blocks are interspersed throughout the file (not BOF or EOF).

There are many related questions on SO about this. For example, [here's one with 12k views](https://stackoverflow.com/q/64687350/9971404).

The only way to do this idempotently is to use two tasks, one for the blank line and one for the block. And it's nasty.

Please consider adding a new option to `blockinfile` to allow prepending/appending blank lines?

### Issue Type

Feature Idea

### Component Name

blockinfile

### Additional Information

<!--- Paste example playbooks or commands between quotes below -->
```yaml (paste below)

```


### Code of Conduct

- [X] I agree to follow the Ansible Code of Conduct
for i, line in enumerate(lines):
                    if insertre.search(line):
                        n0 = i
            if n0 is None:
                n0 = len(lines)
            elif insertafter is not None:
                n0 += 1
        elif insertbefore is not None:
            n0 = 0  
        else:
            n0 = len(lines)  
    elif n0 < n1:
        lines[n0:n1 + 1] = []
    else:
        lines[n1:n0 + 1] = []
        n0 = n1
    
    if n0 > 0:
        if not lines[n0 - 1].endswith(b(os.linesep)):
            lines[n0 - 1] += b(os.linesep)
    lines[n0:n0] = blocklines
    if lines:
        result = b''.join(lines)
    else:
        result = b''
    if module._diff:
        diff['after'] = result
    if original == result:
        msg = ''
        changed = False