2/n Move Accelerator into strategy - remove dispatch functions from Accelerator

[four4fish]

What does this PR do?

Move dispatch(), pre_dispatch() and post_dispatch() to strategies from Accelerator

Part of #10648

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[ananthsub]

is #10884 a prerequisite before this? Should we remove the precision plugin pre-dispatch to simplify this PR?

[four4fish]

is #10884 a prerequisite before this? Should we remove the precision plugin pre-dispatch to simplify this PR?

@ananthsub do #10844 will simplify this PR, but I was trying to have all function moved today, then start move accelerator to strategy (internal fb code freeze in 2 weeks, so hoping speed up). The #10844 is not blocker and can be done separately. After @awaelchli finishes step 4 in #10059, we can remove pre_dispatch for strategy as well. How about we remove both together then?

[awaelchli]

Awesome. I made a follow up to this: #10939