[feature request] add timeout in ExecSync for CRI

[fuweid]

Ⅰ. Issue Description

For now, the ExecSync doesn't have timeout functionality. If we don't have this, the long-time exec will consume the pouchd resource, for example, top/sleep command.

Besides this, the ExecSync uses the spinning check the status of command. It is not ideally and we should use pipe IO to copy and block it. If it is timeout or finish, we will know. Spinning-check isn't good to pouchd.

Ⅱ. Describe what happened

The long-running process will take pouchd down.

Ⅲ. Describe what you expected to happen

ExecSync has the timeout limitation.

Ⅳ. How to reproduce it (as minimally and precisely as possible)

Ⅴ. Anything else we need to know?

@YaoZengzeng

Ⅵ. Environment:

• pouch version (use pouch version):
• OS (e.g. from /etc/os-release):
• Kernel (e.g. uname -a):
• Install tools:
• Others: