feat: pins cli

I find myself writing scripts to manage pins, but I think I'd rather do it on the command line.

Playing around with the API, it seems like the existing methods are fairly amenable to building one:

$ pins set-board ibis-pins  # store the board
$ pins list  # list all pins
$ pins search '*cars'  # list all pins matching a glob pattern
$ pins meta mtcars  # yaml or json blob to stdout
$ pins write mtcars mtcars.parquet --type=parquet
$ pins write mtcars mtcars.csv --type=file
$ pins read mtcars  # not entirely what this should do for non-`file` types
$ pins exists mtcars # exit 0 if exists otherwise exit 1

Is this something y'all are interested in?

Start by reviewing the existing pin API methods that the issue says could support a command-line interface. Clarify the commands and the behavior of read for non-file pin types before implementation; done should include agreed behavior for set-board, list, search, meta, write, read, and exists.