Influxdbv2 support for FreeBSD

Hi everyone, I'm a ports committer on FreeBSD but I stumbled upon a wall for updating our port to v2 (WIP: https://reviews.freebsd.org/D31982). Now in the coming period I have some spare time to work closely together with upstream.
Just to make sure its clear, I can build everything fine from the command line, but not in the official tool that is used to create packages for our repositories.

Here are two topics that I need some assistance from the devs of influxdb:

- I can only fetch files in the fetch phase, when I use GO to build in the build phase, it will fetch the cargo packages, which is not allowed in our ports infrastructure. Is there a way to preseed the cargo crates in a predestined directory? Ideally we would have libflux (rust bits) in a seperate repo. But that's asking to much probably? Is it an option, that I compile the libflux library separately and preseed that into the build for flux? Kinda like a library dependency?

- libflux stopped compiling on my FreeBSD command line with recent rust (1.57), 1.53 was fine
```
Errors out on:
# github.com/influxdata/flux/libflux/go/libflux
ld: error: undefined symbol: fmaf
>>> referenced by std.26131132-cgu.6
>>> std-bf2350936c8d1f1b.std.26131132-cgu.6.rcgu.o:(std::f32::_$LT$impl$u20$f32$GT$::lerp::h40b488c8632f28b9) in archive /usr/ports/lang/influx-flux/work/.cache/go-build/pkgconfig/freebsd_amd64/lib/libflux-c8a084775264730def8e6edf6152b9262a2851e560383a033fcc27eea7e2e87b.a

ld: error: undefined symbol: fma
>>> referenced by std.26131132-cgu.6
>>> std-bf2350936c8d1f1b.std.26131132-cgu.6.rcgu.o:(std::f64::_$LT$impl$u20$f64$GT$::lerp::h0e999cc411e59cca) in archive /usr/ports/lang/influx-flux/work/.cache/go-build/pkgconfig/freebsd_amd64/lib/libflux-c8a084775264730def8e6edf6152b9262a2851e560383a033fcc27eea7e2e87b.a
cc: error: linker command failed with exit code 1 (use -v to see invocation)
*** Error code 2

```

Review the FreeBSD port work in https://reviews.freebsd.org/D31982, focusing on the fetch and build phases, cargo package handling, and the libflux build errors shown in the issue. Done means InfluxDB v2 can be built by FreeBSD's official package tool without disallowed network fetches and libflux links successfully on FreeBSD with recent Rust.

Written by the indexing model from the issue text.