[tmpnet] Add check for vm binaries to network and node start

[marun]

Why this should be merged

Previously, a missing VM binary could fail network start with diagnosis requiring manually reviewing node logs. Now the failure should be obvious.

How this works

• Adds checks to network and node start for the presence of VM binaries for configured chains

How this was tested

CI for regression, manually for usage:

[SynchronizedBeforeSuite] [FAILED] [0.006 seconds]
[SynchronizedBeforeSuite]
/home/me/src/avalanchego/master/tests/e2e/e2e_test.go:41

  [FAILED]
        Error Trace:    /home/me/src/avalanchego/master/tests/fixture/e2e/helpers.go:197
                                                /home/me/src/avalanchego/master/tests/fixture/e2e/env.go:119
                                                /home/me/src/avalanchego/master/tests/e2e/e2e_test.go:60
                                                /home/me/go/pkg/mod/golang.org/[email protected]/src/reflect/value.go:596
                                                /home/me/go/pkg/mod/golang.org/[email protected]/src/reflect/value.go:380
                                                /home/me/go/pkg/mod/github.com/onsi/ginkgo/[email protected]/internal/node.go:486
                                                /home/me/go/pkg/mod/github.com/onsi/ginkgo/[email protected]/internal/suite.go:642
                                                /home/me/go/pkg/mod/github.com/onsi/ginkgo/[email protected]/internal/suite.go:889
                                                /home/me/go/pkg/mod/golang.org/[email protected]/src/runtime/asm_arm64.s:1197
        Error:          Received unexpected error:
                        failed to check VM binary for subnet "xsvm-a": stat /home/me/.avalanchego/plugins/v3m4wPxaHpvGr8qfMeyK6PRW3idZrPHmYcMTt7oXdK47yurVH: no such file or directory
                        failed to check VM binary for subnet "xsvm-b": stat /home/me/.avalanchego/plugins/v3m4wPxaHpvGr8qfMeyK6PRW3idZrPHmYcMTt7oXdK47yurVH: no such file or directory

  In [SynchronizedBeforeSuite] at: /home/me/go/pkg/mod/github.com/stretchr/[email protected]/assert/assertions.go:1495 @ 08/06/24 11:30:34.18

[StephenButtolph]

Seems like there is a trailing space in this error message. Was that intended?

[marun]

Done