Tests: Improve test coverage.

Close #7428
Context suggester: infinite loop in GeolocationContextMapping

Close #7433
[TESTS] Temporarily disable FileBasedMappingsTests.
Test: Fixed the regex in cat.indices/10_basic.yaml

And renamed the file from .yml to .yaml
[TEST] fix issue clearing fielddata breaker introduced in 6950c38a0436ec937797f01fba8d7d95e6d6225f
[TEST] Explicitly clean up actions to be intercepted in IndicesRequestTests before asserting on collected requests

This helps making sure that no further requests are collected once we start asserting on them
[Internal] discovery.id.seed is ignored

Closes #7439, Closes #7437
Stats: add segments.index_writer_max_memory to see index writer's max RAM usage before buffered documents must be written to a new segment

Closes #7438

Closes #7440
[TESTS] Temporary disable field data cache randomization.