Handle command too long failure in typings installer

[sheetalkamat]

In the logs provided in microsoft/vscode#46025 , typing installer failed to install type packages because the command was too long. When TI installer fails, there is no attempt to reinstall which means user doesnt get intellisense from these typings hence we should avoid TI installation failures whenever possible.

[RyanCavanaugh]

This seems needlessly confusing. How about something like this?

    /*@internal*/
    export function installNpmPackages(npmPath: string, tsVersion: string, packageNames: string[], install: (command: string) => boolean) {
        let hasError = false;
        const remaining = packageNames.slice();
        while (!hasError && remaining.length > 0) {
            const batch = takePackages(remaining);
            const command = `${npmPath} install --ignore-scripts ${batch.join(" ")} --save-dev --user-agent="typesInstaller/${tsVersion}"`;
            hasError = install(command) || hasError;
        }
        return hasError;
}

    function takePackages(packages: string[]): string[] {
        let remainder = 7500;
        const result: string[] = [];
        while (packages.length > 0 && remainder > 0) {
            const p = packages.pop();
            remainder -= (p.length + 1); // +1 for space
            result.push(p);
        }        
        return result;
    }

[sheetalkamat]

I dont want to create duplicate array if cmd is going to succeed. But let me see if i can infuse this with my approach and comeup with something better.

[sheetalkamat]

@mhegazy do we want this for 2.8.3 ?

[mhegazy]

I think we are done for 2.8.3 for now. we already snapped the VS release.