fix(alias): show the full command in 'alias list'

Description

glab alias list truncated the command column at 70 characters, so long aliases couldn't be read or copied out of the output. That limit was a leftover default from the 2020 move to uitable (6c4fe1c2) rather than a decision about aliases, and alias list was the last caller in the codebase still setting it. Background in this discussion.

This removes the truncation and enables wrapping instead, so the full command prints at any terminal width. Non-TTY output was already untruncated, so nothing scripted changes.

Note: this code was written by an LLM.

How has this been tested?

Manually, against a long alias at 80- and 40-column terminals.

The command's unit tests can't observe this behavior: truncation is gated on the table printer's package-level IsTTY, which is set in cmd/glab/main.go and stays false under test.

Screenshots (if appropriate):

Before:

> glab alias list
Alias         Command
create_group  !glab api --method POST /groups --form name=$1 --form path=$2 --for...

After, on an 80-column terminal:

> glab alias list
Alias         Command
create_group  !glab api --method POST /groups --form name=$1 --form path=$2
              --form parent_id=$(glab api /groups/$3 --output ndjson | jq .id)