Add config option equivalent to --disable-reporting

[dmitrydonskih]

Request

Add configuration option to disable sending stat reports to stats.grafana.org.

Use case

When Alloy runs in closed network without access to internet, sending stats reports fails, it floods own logs with errors and therefore should be disabled.
Currently the only way to disable it is to issue command-line option --disable-reporting.
On linux, this requires modification of systemd service.
On windows, installed service runs different executable (alloy-service-windows-amd64.exe), so modifying command-line options is not possible (at least not documented).
We definitely need a more convenient way to control this feature.

[mzurborg-scopevisio]

Please prioritize this.

We want to roll-out alloy to our customers who use parts of our software in their local networks on Windows-based computers in order to be able to collect metrics and logs and we cannot (due to strict data protection agreements with our customers) do this unless this analytics can be easily disabled via config file.

As @dmitrydonskih stated above, easily disabling reporting for the windows service installer is currently neither supported nor documented.

This sadly needs to be adressed in the next 6-8 weeks or we won't be able to use alloy at all.

The config file should support disabling this as such:
analytics { reporting_enabled = false }