[javasrc2cpg] Add name mangling for pattern locals that conflict with locals in the enclosing scope

[johannescoetzee]

This PR builds on #5305 and is a follow-up to #5305 and adds name mangling for locals that conflict with hoisted pattern locals. Where conflicting variables have the same types as well, a single local is shared instead.

static void foo(Object o) {
  if (o instanceof String value) {
    sink(value);
  }
  // mangled
  int value;
}

static void foo(Object o) {
  if (o instanceof String value) {
    sink(value);
  }
  if (o instanceof Integer value) {
    // mangled
    sink(value);
  }
}

static void foo(Object o) {
  switch (o) {
    case Integer value -> sink(value);
    // not mangled since the local is enclosed in a block in the body of the switch entry
    case Boolean value -> sink(value);
  }
  if (o instanceof String value) {
    // not mangled since the switch locals are all enclosed
    sink(value);
  }
}

static void foo(Object o) {
  {
    if (o instanceof String value) {
      sink(value);
    }
  }
  {
    // not mangled since the pattern local is enclosed in the block above
    int value = 2;
    sink(value);
  }
}

// single local shared
static void foo(Object o) {
    if (o instanceof String s) {
        sink0(s);
    }
    if (o instanceof String s) {
        sink1(s);
    }
    // This s must be initialized before using it, so it will always overwrite the value of the
    // pattern variable, hence avoiding false positives.
    String s = "safe";
    sink2(s);
}