Dynamically handle worksheet size

[tadam313]

Upon worksheet creation, the column count/row count values are burnt-in, meaning a worksheet area won't extend as the user inserts new entries. This eventually end up causing an error if the content grows too big. The insertion logic should be aware of this behaviour and dynamically increase the worksheet area by X lines/columns. (where X should be significantly bigger than the amount of entries being inserted to avoid doing this on every insert)