test(e2e): Section 1 connection form scenarios (#1050)

[ZhuchkaTriplesix]

Summary

Restores the connection-form scenarios of Section 1 (e2e_connection_form_test.dart), dropped in 8b876c1, and makes them pass: a connection is created through the New connection dialog and the form of each type (PostgreSQL, MySQL, Redis, MongoDB by URI; SQLite through its fields).

Why they failed (all five with Bad state: No element in enterText):

• No type was ever selected. The test opened the Database type dropdown and tapped find.text(label).hitTestable().last. The menu's items come before the grid cards in the element tree, so that was a card; the open MenuAnchor has consumeOutsideTap: true, so the tap only closed the menu. Next stayed disabled, the form never opened, and waitFor timed out silently.
• The card's label is covered. At the test window size the type grid is shorter than a card and the dialog footer covers the label, so the scenario taps the card itself.
• MongoDB is in the second row, not built until the grid scrolls: scrollUntilVisible first.
• MongoDB's URI field is behind "Use connection string": the scenario checks it.
• Wrong expectations for MySQL / Redis: for a URI connection they keep host empty and do not name it after the URI's host. Every form moves the URI to the secure store, so the scenario checks it there, and waits for the new name in the sidebar.

waitFor now asserts what it waited for and pickType checks that Next left the type dialog, so a future break names its step.

Refs #1050 (folders and moving connections into them are still not covered).

Test plan

• CI: all five form scenarios and the whole suite pass on the PR head (no local runs, per team rule)