Bump VERSION to 1.0.0 and cut the first tagged release of vpp-maglev.
Also in this commit:
- maglevc: MAGLEV_SERVER env var as an alternative to the --server
flag, matching the MAGLEV_CONFIG / MAGLEV_GRPC_ADDR convention on
the other binaries. The flag takes precedence when both are set.
- Rename cmd/maglevd -> cmd/server and cmd/maglevc -> cmd/client so
the source directory names are decoupled from binary names (the
frontend and tester commands already followed this convention).
Build outputs and the Debian packages are unchanged.
