Add benchmark script

[pocke]

The current benchmarking result is the following:

# Benchmarking #to_sql mehtod

## Wihtout AR::Originator
ruby benchmark/to_sql.rb
-- create_table(:posts, {:force=>true})
   -> 0.0061s
ruby 3.4.0dev (2024-02-06T03:19:56Z master 4f6b827e98) [arm64-darwin21]
Warming up --------------------------------------
       without where     5.921k i/100ms
with single condition
                         2.714k i/100ms
with multiple condition
                         1.517k i/100ms
Calculating -------------------------------------
       without where     59.719k (± 0.7%) i/s -    301.971k in   5.056838s
with single condition
                         27.049k (± 0.9%) i/s -    135.700k in   5.017249s
with multiple condition
                         15.021k (± 1.8%) i/s -     75.850k in   5.051172s

## With AR::Originator
ruby -r activerecord/originator benchmark/to_sql.rb
-- create_table(:posts, {:force=>true})
   -> 0.0046s
ruby 3.4.0dev (2024-02-06T03:19:56Z master 4f6b827e98) [arm64-darwin21]
Warming up --------------------------------------
       without where     1.116k i/100ms
with single condition
                       543.000 i/100ms
with multiple condition
                       269.000 i/100ms
Calculating -------------------------------------
       without where     11.178k (± 0.8%) i/s -     56.916k in   5.092079s
with single condition
                          5.512k (± 1.5%) i/s -     27.693k in   5.025152s
with multiple condition
                          2.635k (± 4.6%) i/s -     13.181k in   5.012587s
# Benchmarking SELECT Query

## Wihtout AR::Originator
ruby benchmark/select_query.rb
-- create_table(:posts, {:force=>true})
   -> 0.0048s
ruby 3.4.0dev (2024-02-06T03:19:56Z master 4f6b827e98) [arm64-darwin21]
Warming up --------------------------------------
       without where     5.911k i/100ms
with single condition
                         2.717k i/100ms
with multiple condition
                         1.522k i/100ms
Calculating -------------------------------------
       without where     58.395k (± 2.5%) i/s -    295.550k in   5.064565s
with single condition
                         26.948k (± 1.8%) i/s -    135.850k in   5.042894s
with multiple condition
                         15.208k (± 0.7%) i/s -     76.100k in   5.004290s

## With AR::Originator
ruby -r activerecord/originator benchmark/select_query.rb
-- create_table(:posts, {:force=>true})
   -> 0.0050s
ruby 3.4.0dev (2024-02-06T03:19:56Z master 4f6b827e98) [arm64-darwin21]
Warming up --------------------------------------
       without where     1.135k i/100ms
with single condition
                       556.000 i/100ms
with multiple condition
                       288.000 i/100ms
Calculating -------------------------------------
       without where     11.413k (± 2.0%) i/s -     57.885k in   5.074069s
with single condition
                          5.490k (± 2.1%) i/s -     27.800k in   5.066375s
with multiple condition
                          2.869k (± 2.6%) i/s -     14.400k in   5.023409s