Fix issue #1364: Removing last row incorrect behavior

[TimGa]

This is:

- [X] a bugfix
- [ ] a new feature

Checklist:

• Changes are covered by unit tests
• Code style is respected
• Commit message explains why the change is made (see https://github.com/erlang/otp/wiki/Writing-good-commit-messages)
• CHANGELOG.md contains a short summary of the change
• Documentation is updated as necessary

Why this change is needed?

This PR fixes #1364 Removing last row incorrect behavior

Description:
$highestRow = $this->getHighestDataRow(); was calculated after $this->getCellCollection()->removeRow($pRow + $r); - this is the root reason for incorrect rows removal because removing last row will change '$this->getHighestDataRow()' value, but removing row from the middle will not change it. So, removing last row causes incorrect $highestRow value that is used for wiping out empty rows from the bottom of the table:

for ($r = 0; $r < $pNumRows; ++$r) {
    $this->getCellCollection()->removeRow($highestRow);
    --$highestRow;
}

To prevent this incorrect behavior I've moved highest row calculation before row removal.
But this still doesn't solve another problem when trying remove non existing rows: in this case the code above will remove $pNumRows rows from below of the table, e.g. if $highestRow=4 and $pNumRows=6, than rows 4, 3, 2, 1, 0, -1 will be deleted. Obviously, this is not good, that is why I've added $removedRowsCounter to fix this issue.
And finally, moved Exception to early if statement to get away from unnecessary 'if-else'.

[TimGa]

Hi, @PowerKiKi
Could you please review this PR?

[minhtranahri]

Hi @TimGa , i think just remove this code is enough

for ($r = 0; $r < $pNumRows; ++$r) {
    $this->getCellCollection()->removeRow($highestRow);
    --$highestRow;
}

[TimGa]

Hi @minhtranahri , you are right, removing this part of code will solve the issue, but somebody wrote it for some reason, that is why I decided to keep it. This part of code could be used for deleting cache stuff or some other implicit actions i don't know. So I decided to fix this issue without removing existing lines of code.

[minhtranahri]

Hi @TimGa, thanks for clarifying and being careful. Very appreciate!

[PowerKiKi]

Thank you for the well crafted PR and your patience.