Should inlineSymbolSearch code be removed?

Created by: lguychard

Inline symbol search currently seems to be enabled by default by a feature flag, but neither myself nor @felixfbecker can get it to work. Yet nobody has complained about it breaking.

In addition, it represents quite a lot of code that:

• We'd need to overhaul to bring up to our targeted quality standards
• Might interfere with some planned rewrites around better handling DOM mutation.

Should we just kill the feature and remove all associated code?

cc @sqs