Table efficiency

Hello great people of charm community,
i have a question regarding the table component and it's responsiveness with the increase of table rows.
We try to use it in an app we're developing and everything was good until we started getting to multiple thousand rows where we noticed a significant degradation in responsiveness and a noticeable spike in cpu-usage when scrolling up/down.

Some details:
We have a table with 6 columns. When the row count is "low", <1k the moveup/down calls are executed fairly quickly, we put some log printfs to measure the time in the Update()

```
case key.Matches(msg, keybindings.DefaultKeyMap.Down):
m.Log.Printf("Update: Move down\n")
activeTable.MoveDown(1)
m.Log.Printf("Update: Move down finished\n")
```

For the "low" row count (~<1k) the moves take ~0.002 seconds, which then looks nice and responsive:
```
SC: 14:42:47.489481 update.go:374: Update: Move down
SC: 14:42:47.491627 update.go:376: Update: Move down finished
SC: 14:42:47.524541 update.go:374: Update: Move down
SC: 14:42:47.526015 update.go:376: Update: Move down finished
SC: 14:42:47.550793 update.go:374: Update: Move down
SC: 14:42:47.553671 update.go:376: Update: Move down finished
```

But as the row count grows, time and cpu-load to execute activeTable.MoveDown() grows significantly, example for 4.5k rows, takes up to 0.5 seconds to do one movedown(), making the app very, very sluggish :smile:

```
SC: 15:20:04.758040 update.go:374: Update: Move down
SC: 15:20:05.055713 update.go:376: Update: Move down finished
SC: 15:20:05.261438 update.go:374: Update: Move down
SC: 15:20:05.607520 update.go:376: Update: Move down finished
SC: 15:20:05.609510 update.go:374: Update: Move down
SC: 15:20:05.925371 update.go:376: Update: Move down finished
SC: 15:20:05.926199 update.go:374: Update: Move down
SC: 15:20:06.121864 update.go:376: Update: Move down finished
```
By having a brief look at the code, looks like this extra time might come from the
https://github.com/charmbracelet/bubbles/blob/85da9addbaf22222aed087d7afae744925ec2ef3/table/table.go#L312-L314
call to UpdateViewPort()
which for every movedown() iterates and makes a copy of the entire table in renderedRows?
https://github.com/charmbracelet/bubbles/blob/85da9addbaf22222aed087d7afae744925ec2ef3/table/table.go#L243-L247

If this guess is correct, could you perhaps optimize this in some way?
Perhaps render only rows there are "visible" instead of the whole table?
Or if i'm miss-using the table in some way point me on how to better do this?

Many thanks!