Perf: Make output channel logging faster in web

[mjbvz]

Steps to Reproduce:

1. Set "typescript.tsserver.log": "verbose"
2. On insiders.vscode.dev, open a JS/TS file and type a bunch in the file to trigger TS Server requests
3. Open the output panel and look at the TypeScript Server log section

Bug
The output log updates slowly and continues updating long after you finish typing

We are using vscode.OutputChannel. I've debugged this and believe that the TS logs all of the information quickly. It seems like the issue is with the display/update of the output channel content in the UI

[mjbvz]

I believe the root cause is the FileLogger. In particular, every call to the FileLogger.log takes between 150 and 400ms on my machine, and TS makes a large number of log calls per second if you type quickly

[sandy081]

@mjbvz I assume this is what you are observing (following your steps) that after opening the log, content keeps updating for a while

before.mp4

After

Improved it using throttler and this is how it is after - after output is opened, content is updated just once.

after.mp4