Blender Git Loki

Fix T88551: Crash accessing uninitialized tool settings

Tool settings for sequencer were not initialized, which caused crash
when adding strips.

There was fix for same issue in versioning rB0f81dafe6cec, but
subversion was not bumped, so files with uninitialized tool settings
may still exist.

Add `SEQ_tool_settings_get()` accessor function that will initialize
tool settings if they are missing. Change operator code to use
`SEQ_tool_settings_fit_method_get()` function instead of accessing
tool settings directly

Reviewed By: campbellbarton

Differential Revision: https://developer.blender.org/D11383