Convert quick fixes to bulk actions

[citizenmatt]

The following Quick Fixes have been converted into bulk (scoped) actions, that work across method, class, file, folder, project and solution:

• Convert to CompareTag
• Convert to generic overload (GameObject.GetComponent, GameObject.AddComponent, ScriptableObject.CreateInstance)
• Combine setting parent with object creation ("Use Instantiate with parent argument")
• Convert coalescing operator to conditional
• Remove redundant attribute

The remove redundant attribute quick fix is now a "redundant code" quick fix and has additional features/implications:

• The quick fix is executed as part of removing redundant code in Code Cleanup
• Adds "remove redundant code in XXX" bulk fixes, which remove ALL redundant code, such as unnecessary this., dead code, etc.
• The bulk quick fix will remove all redundant Unity attributes in scope, not just the attribute type under the caret, so it will remove any incorrectly applied [SerializeField], [InitializeOnLoad], [HideInInspector], etc.

[citizenmatt]

Another implication: if a non-serialisable base class has a [SerializeField] attribute, we currently consider that as redundant - we don't check for derived classes that might be serialised. The remove redundant attribute bulk fix will remove this attribute, even though it is valid.

This needs to become a show-stopper: RIDER-18729

(See #1650 for tracking in the 2020.2 milestone. I want to make sure this isn't lost)

[citizenmatt]

@krasnotsvetov can you verify what kinds we should be ignoring here? We obviously want to work for visible document and SWEA. These changes require OTHER to quickly find highlightings to fix, but what about the other values?

[krasnotsvetov]

I am not sure, that we should ignore INCREMENTAL_SOLUTION_ANALYSIS, but ignoring GLOBAL_WARNINGS is ok. Only performance critical inspections (and burst in future) will use global stage

[krasnotsvetov]

LGTM