[Search:Connectors:New connector page]Issues with Connector input field

[L1nBra]

Description
For the user, especially using assistive technology, it should be clear where he/she is at the moment, how to interact with the element. User shouldn't be confused by duplicate, strange announcements or strange sentence structures.

Preconditions
Stateful Connectors -> New connector page is opened.
Use Screen Reader (NVDA).

Steps to reproduce

1.Navigate to Connector field while using only keyboard by pressing Tab key.
2.Observe Screen Reader announcement.
3.Navigate through the opened list.
4.Observe Screen Reader announcement.
5.Press Enter on any connector to select it.
6.Observe Screen Reader announcement.
7.Delete selection from the field by pressing Tab key.
8.Observe the field.

NVDA Speech Viewer + UI element
step 2

step4

step6

step8

Actual Result

• Step2: duplicate announcement of the dialog and its' information.
• Step4: before each option in the list, "34 results available" are announced (total items in the list). After announcing option name, screen reader separately announces "dot" (because in html dot symbol is separately written), example: "Customized connector ."(the dot here is announced). Self managed, Tech preview badges are announced as well and after "not checked" announcement, the name of the option is announced again.
• Step6: after selecting option from the list, list is not present anymore on the screen. Screen reader still announces all available options according to the selection present in the Connector input field and it announces instructions how to move through the options, select them, but if user press up/down arrow keys, Enter key - nothing happens (because list is not present below the field at the moment).
• Step8: after deleting selected entry from Connector field when pressing Backspace key - list doesn't appear below the field.

Expected Result

• Step2: dialog with it's information is announced only one time.
• Step4: total number or results are not announced before each option - they are announced only one time (something like this when announcing the list: "list with 34 items"). Dot is not announced by the screen reader (should not be added separately in html between comas (".")). Clear announcement of list option - option is not duplicated, either badges are not announced or at least the sentence structure should be different (now it is not clear what exactly user is checking, what is not checked. Is it Self managed or Customized connector).
• Step6: announcement should be clear and only about the Connector field with the selection present in it - no announcement about instructions of list (because now user expects changes with up/down arrow keys, Enter key - but nothing happens).
• Step8: list appears below the Connector field (because if you delete entry by pressing x button in Connector field - list appears).

Meta Issue

Kibana Version: 8.16.0-SNAPSHOT

OS: Windows 11 Pro

Browser: Chrome Version 129.0.6668.101 (Official Build) (64-bit)

Screen reader: NVDA

WCAG or Vendor Guidance (optional)

• Understanding SC 1.3.1: Info and Relationships (Level A)(https://www.w3.org/WAI/WCAG22/Understanding/info-and-relationships.html)
• Understanding SC 4.1.2: Name, Role, Value (Level A)(https://www.w3.org/WAI/WCAG22/Understanding/name-role-value.html)
• Understanding SC 3.3.2: Labels or Instructions (Level A)(https://www.w3.org/WAI/WCAG22/Understanding/labels-or-instructions.html)

Related to: https://github.com/elastic/search-team/issues/8256

[elasticmachine]

Pinging @elastic/kibana-accessibility (Project:Accessibility)