[TableGen] Add PatternSymbolResolver for resolving symbols bound in patterns

    We can bind symbols to op arguments/results in source pattern and op results in
    result pattern. Previously resolving these symbols is scattered across
    RewriterGen.cpp. This CL aggregated them into a `PatternSymbolResolver` class.

    While we are here, this CL also cleans up tests for patterns to make them more
    focused. Specifically, one-op-one-result.td is superseded by pattern.td;
    pattern-tAttr.td is simplified; pattern-bound-symbol.td is added for the change
    in this CL.

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PiperOrigin-RevId: 241913973