Summary:
When updating tablet metadata file we create temporary file, write to this file, then rename it to regular filename.
It could happen that crash happens during this process (even in a different thread).
So temporary file remains in tablet-meta folder.
Added logic to cleanup such file on server startup.

The test TabletSplitRemoteBootstrapEnabledTest.TestSplitAfterFailedRbsCreatesDirectories uses artificial crash.
So during such crash we could generate temporary tablet metadata file.
Then test waits until tablet metadata on different nodes matches, but because of temporary metadata it never matches.
Jira: DB-14691

Test Plan: ./yb_build.sh asan -n 100 --cxx-test integration-tests_tablet-split-itest --gtest_filter TabletSplitRemoteBootstrapEnabledTest.TestSplitAfterFailedRbsCreatesDirectories -- -p 8

Reviewers: timur

Reviewed By: timur

Subscribers: ybase

Tags: #jenkins-ready

Differential Revision: https://phorge.dev.yugabyte.com/D40935