Remove required '@' prefix for file paths in 'influx' CLI

[sanderson]

Proposal:
Remove the required @ prefix when specifying file paths in the influx CLI. It breaks any shell's native tab-completion.

Desired behavior:
I want to be able to use my shell's native tab-completion to quickly type file paths when using the influx CLI.

Use case:
Ease of use.

[jsteenb2]

toooootally agree, we should support piping everywhere as well withou the arcane - requirement

[imogenkinsman]

As part of the story I think it's important to understand why it's designed this way and if there are any implications for changing it, because I don't have context on that right now.

[sranka]

#17398 introduces a new --file (or -f ) flag that let the user specify the file to write

[sanderson]

@sranka does your PR only introduce it to the write command? This change needs to happen with all commands that accept a file as input.:

influx write
influx query
influx task create

There may be others

[sranka]

Only the write command

[kelwang]

this is fixed by #17398

[sanderson]

@kelwang #17398 only address the write command. The query and task create commands still need to be updated with the --file flag.