[Accessibility] Improve Management Table Accessibility

[elasticmachine]

Original comment by @aphelionz:

This applies Security (Users / Roles) and Logstash Pipelines

1. The search box is not unlabeled but a clear auditory indicator that it is indeed a search/filter box will be helpful, instead of just reading the placeholder text.
2. The "Select All" checkbox needs to have a clear auditory cue
3. The table headers are inaccessible - you cannot sort and additionally they are never even read by the screen reader
4. The rows are thus unclear - each checkbox needs to be labeled as "select row" and each link in the row needs to have the header read along with it i.e. Full Name: beats_internal

[cjcenizal]

Item 2 will be addressed by #20739.

Items 1, 3, and 4 are partially addressed by EUI but still need improvement in EUI.

[elasticmachine]

Pinging @elastic/kibana-security

[myasonik]

Everything is either addressed by the current UI or is an issue entirely contained by EUI which will require no further work in Kibana once EUI has a fix