[CQ] introduce null-safe OpenApi wrappers

[pq]

Currently there are a number of common platform accesses that are not safe, prone to runtime exceptions and spam the inspection log with nullability warnings. This change introduces a host of wrappers around common IntelliJ Open API calls that introduce null-safety, reducing NPE risk, quieting 86 "Nullability and data flow problems" inspections.

Specifically, this change introduces and migrates calls to new OpenApiUtils utility methods:

• safeRunWriteAction
• safeInvokeAndWait
• safeInvokeLater
• getModules
• getLibraryTable
• getContentRoots

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