[Search:Search Applications:Content page]Issues with the tables in Indices, Schema tabs

[L1nBra]

Description
For user it should be clear what table is about, how many rows, columns it contains. Without any strange or unexpected announcements. Buttons present in the table should be announced with their state, especially the collapsed/expanded buttons.
Also if no items found when searching, filtering user also should be informed about it not only visually but user using assistive technology should hear this information.

Preconditions
Stateful Search Applications -> Content page, Indices or Schema tab is opened.
Search application is added.
Use Screen Reader (NVDA).

Steps to reproduce

1.Using only keyboard Navigate to table by pressing T key in Indices (or Schema) tab.
2.Observe screen reader.
3.Navigate to Remove this index button in Indices tab table.
4.Press Enter.
5.Navigate to Cancel button.
6.Press Enter.
7.Observe screen reader.
8.Navigate to More info button in Schema tab table.
9.Observe the page and screen reader.
10.Navigate to Field types button.
11.Press Enter.
12.Select id option from the list (or any other which would provide no results).
13.Press Esc.
14.Observe the page and screen reader.

UI elements + NVDA Speech Viewer
[step2]

[step7]

[step9]

[step14]

Actual Result

1)[step2] Announcement that table contains 4 rows, following "table contains 3 rows out of 3".
2)[step2] Caption announcement that table contains specific number of rows, without short summary about the table (what it is for, what data it contains).
3)[step7] When canceling Removal of index - announcement about row 3 is made.
4)[step9] Announcement of column 5 when visually 4 columns are present in the table.
5)[step9] More info button is only announced as button without state.
6)[step14] No items found present in the table but it is not announced to the user. Same with table in Indices tab when you provide random text in Search field - no items found only are visually present in the table, but not announced (that search did not provide any results).

Expected Result

1)[step2] Correct announcement about how many rows are present is made for the user (in this case table has 3 rows). Caption should provide short summary for the user about the table (not only mention how many rows there are. Row number is already announced when navigating to the table).
2)[step7] Announcement only about Remove button is made.
3)[step9] Number of columns announced is the same as how much visually user can see them (in this case 4 columns). Button is announced "More info button collapsed" (and "More info button expanded" when user press Enter on it).
4)[step14] Announcement about "No items found" after search, filtering is made for the user when there are no results.

Meta Issue

Kibana Version: 8.17.0-SNAPSHOT

OS: Windows 11 Pro

Browser: Chrome Version 130.0.6723.70 (Official Build) (64-bit)

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)

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

[elasticmachine]

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