Add a "Start graceful restart" button at `127.0.0.1:7070/?page=commands`

[pasabanov]

Currently only the "Start graceful shutdown" and "Force shutdown" buttons are present in the commands page.

I propose adding a "Start graceful restart" button, like the one in the Java I2P webconsole.

It would be beneficial since it seems to me that the workarounds are not working properly or are inconvenient:

• Currently you would either execute service i2pd restart, but in my experience it never performed graceful restart,
• or manually press "Start graceful shutdown", wait 10 minutes and then manually start i2pd again, which is not very convenient.

Adding this button would result in a convenient and explicit way to perform graceful restart.