Using runner tag 'poetry-56' replacing test-3.5 job load

aiohttp updated to v3.7.1
multidict updated to v5.0 which drops Py 3.5 support

Requires Python 3.6.8
Remove test job

Not added as a direct dependency, since it is a DuniterPy dependency
And Silkaj won't get away from DuniterPy, nor DuniterPy will stop using
base58.

Not compatible with Poetry v1.0
Update dependencies

- Set poetry-core v1.0.0 as requirement and new build system
https://python-poetry.org/blog/announcing-poetry-1-1-0.html

- fix 'nd' -> 'th'

change the tests to match the new behavior

    * for display
    * as input

    * display
    * parameter
* change tests/test_wot and test_end_to_end to match new behavior

* change in choose_identity() will affect commands `cert` and `membership` display.

* Change test_end_to_end.py to match new behavior

    * in the display
    * as parameter

   * for each pubkey in the tx confirmation
   * when sending the transaction

   * modify the function display_pubkey() and related tests

    and related tests

    check_public_key() was used for money- and wot- related commands that have differend needs.
    * remove check_public_key()
    * create is_pubkey_and_check(), check_pubkey_format() and validate_checksum()
    * create related tests
    * modify tx, balance and history commands.
    * use is_pubkey_and_check() in `id` command and solve #320

    * change imports in silkaj.money to prevent loop dependency

    * gets a pubkey in for input
    * returns the checksum

* move test_display_amount() and test_display_pubkey() from test_unit_tx.py to test_tui.py

Add tests for prefix()
Just import tx_history
Rework prefix()

To avoid non-necessary requests,
which wasn't working due to the membership tests which was closing the client

Found #335

Remove useless monkeypatch

- #314: dry-run option

To know that an uid and a pubkey can be passed as argument
It is not possible to add an help on argument() as for option()
https://click.palletsprojects.com/en/7.x/arguments/