Add entity that reads filled searchbox on new and old hosts pages

[LadislavVasina1]

Add an entity read_filled_searchbox to the host.py (old hosts UI) and all_hosts.py (new hosts UI) so that it can be used in the automation.

Usage:

• Old UI

with target_sat.ui_session() as session:
    session.host.search('some_search_string')
    read_searchbox_value = session.host.read_filled_searchbox()
    print(read_searchbox_value)

• New UI

with target_sat.ui_session() as session:
    session.all_hosts.search('some_search_string')
    read_searchbox_value = session.all_hosts.read_filled_searchbox()
    print(read_searchbox_value)

[vsedmik]

Codewisely looks good to me, one question - shouldn't this be always True?

read_searchbox_value == 'some_search_string'

Or what should I expect to change here and why?

[LadislavVasina1]

@vsedmik I don't know if I get your last comment, where do you specifically see usage of the == operator?

[vsedmik]

@LadislavVasina1 I just meant the example you provided in the PR description

with target_sat.ui_session() as session:
    session.all_hosts.search('some_search_string')
    read_searchbox_value = session.all_hosts.read_filled_searchbox()
    # here I would always expect read_searchbox_value == 'some_search_string'
    # so I just wondered why we need the read function

[LadislavVasina1]

@vsedmik I made this read function for vijay so he has an easier job in his current work, if that's what you are asking

[vijaysawant]

These changes are working absolutely fine, I tested it locally, and now running in CI as part of this robottelo PR SatelliteQE/robottelo#16641
These changes are here in another airgun PR #1593