Add short timeout to version check HTTP requests

**Related command**
`az vmss reimage --debug --help`

**Is your feature request related to a problem? Please describe.**

In case of low transfer speed to `raw.githubusercontent.com`, commands with `--help` argument hangs for a long time. This seem largely suspicious and unhelpful when dealing with `--help` commands.

**Describe the solution you'd like**
IIUC this HTTP requests are related to checking version of CLI. If that's the case, I think those requests should have some fixed deadline/timeout which when hit, may produce a warning message. Taking general slowness of Azure CLI, perhaps timeout of 500-1000 ms should not be that bad, comparing to my which was 80 seconds.

**Additional context**

```
$ az vmss reimage --debug --help
...
To search AI knowledge base for examples, use: az find "az vmss reimage"

urllib3.connectionpool: Starting new HTTPS connection (1): azure.microsoft.com:443
urllib3.connectionpool: https://azure.microsoft.com:443 "HEAD / HTTP/1.1" 301 0
cli.azure.cli.core.util: Connectivity check: 1.255078981999759 sec
urllib3.connectionpool: Starting new HTTPS connection (1): raw.githubusercontent.com:443
urllib3.connectionpool: https://raw.githubusercontent.com:443 "GET /Azure/azure-cli/main/src/azure-cli-core/setup.py HTTP/1.1" 200 1246
urllib3.connectionpool: Starting new HTTPS connection (1): raw.githubusercontent.com:443
urllib3.connectionpool: https://raw.githubusercontent.com:443 "GET /Azure/azure-cli/main/src/azure-cli-telemetry/setup.py HTTP/1.1" 200 679
cli.knack.cli: Event: Cli.PostExecute []
az_command_data_logger: exit code: 0
cli.__main__: Command ran in 82.614 seconds (init: 0.256, invoke: 82.358)
0 ✓ (1m23s) 15:37:57 invidian@dellxps15mateusz ~/repos/kinvolk/aksiknife-copy (⎇ master)$ az version
Azure-cli Azure-cli-core Azure-cli-telemetry
----------- ---------------- ---------------------
2.42.0 2.42.0 1.0.8