Now reading API keys from a user is done with the get_api_key wrapper
method, rather than directly fetching it from the user object.
Also, every place where an action should be done for each API key is now
using get_all_api_keys. This method returns for the moment a single-item
list, containing the specified user's API key.
This commit is the first step towards allowing users have multiple API
keys.
The only changes visible at the AST level, checked using
https://github.com/asottile/astpretty, are
zerver/lib/test_fixtures.py:
'\x1b\\[(1|0)m' ↦ '\\x1b\\[(1|0)m'
'\\[[X| ]\\] (\\d+_.+)\n' ↦ '\\[[X| ]\\] (\\d+_.+)\\n'
which is fine because re treats '\\x1b' and '\\n' the same way as
'\x1b' and '\n'.
Signed-off-by: Anders Kaseorg <andersk@mit.edu>