feat: add vmagent role

[zekker6]

Added vmagent installation role. Installation is made by using binary from github releases.

[zekker6]

@bykvaadm I've updated notes we discussed:

• remove unneeded flags for vmagent
• unify naming
• parameters for proxy
• atomic operation for binary installation
• option for download to local host for binary

[zekker6]

@bykvaadm seems like this one wasn't merged eventually after branch updates :)