`ActiveSupport::ParameterFilter.precompile_filters` precompiles filters
that otherwise would be passed directly to `ParameterFilter.new`.
Depending on the quantity and types of filters, precompilation can
improve filtering performance, especially in the case where the
`ParameterFilter` instance cannot be retained, such as with per-request
instances in `ActionDispatch::Http::FilterParameters`.

**Benchmark script**

  ```ruby
  # frozen_string_literal: true
  require "benchmark/ips"
  require "benchmark/memory"
  require "active_support"
  require "active_support/parameter_filter"

  ootb = [:passw, :secret, :token, :_key, :crypt, :salt, :certificate, :otp, :ssn]
  mixed = [:passw, "secret", /token/, :crypt, "salt", /certificate/, "user.otp", /user\.ssn/, proc {}]
  precompiled_ootb = ActiveSupport::ParameterFilter.precompile_filters(ootb)
  precompiled_mixed = ActiveSupport::ParameterFilter.precompile_filters(mixed)

  params = {
    "user" => {
      "name" => :name,
      "email" => :email,
      "password" => :password,
      "ssn" => :ssn,
      "locations" => [
        { "city" => :city, "country" => :country },
        { "city" => :city, "country" => :country },
      ],
    }
  }

  Benchmark.ips do |x|
    x.report("ootb") do
      ActiveSupport::ParameterFilter.new(ootb).filter(params)
    end
    x.report("precompiled ootb") do
      ActiveSupport::ParameterFilter.new(precompiled_ootb).filter(params)
    end
    x.compare!
  end

  Benchmark.ips do |x|
    x.report("mixed") do
      ActiveSupport::ParameterFilter.new(mixed).filter(params)
    end
    x.report("precompiled mixed") do
      ActiveSupport::ParameterFilter.new(precompiled_mixed).filter(params)
    end
    x.compare!
  end

  Benchmark.memory do |x|
    x.report("ootb") do
      ActiveSupport::ParameterFilter.new(ootb).filter(params)
    end
    x.report("precompiled ootb") do
      ActiveSupport::ParameterFilter.new(precompiled_ootb).filter(params)
    end
  end

  Benchmark.memory do |x|
    x.report("mixed") do
      ActiveSupport::ParameterFilter.new(mixed).filter(params)
    end
    x.report("precompiled mixed") do
      ActiveSupport::ParameterFilter.new(precompiled_mixed).filter(params)
    end
  end
  ```

**Results**

  ```
  Warming up --------------------------------------
                  ootb     2.151k i/100ms
      precompiled ootb     4.251k i/100ms
  Calculating -------------------------------------
                  ootb     21.567k (± 1.1%) i/s -    109.701k in   5.086983s
      precompiled ootb     42.840k (± 0.8%) i/s -    216.801k in   5.061022s

  Comparison:
      precompiled ootb:    42840.4 i/s
                  ootb:    21567.5 i/s - 1.99x  (± 0.00) slower
  ```

  ```
  Warming up --------------------------------------
                 mixed     1.622k i/100ms
     precompiled mixed     2.455k i/100ms
  Calculating -------------------------------------
                 mixed     16.085k (± 1.3%) i/s -     81.100k in   5.042764s
     precompiled mixed     24.640k (± 1.0%) i/s -    125.205k in   5.081988s

  Comparison:
     precompiled mixed:    24639.6 i/s
                 mixed:    16085.0 i/s - 1.53x  (± 0.00) slower
  ```

  ```
  Calculating -------------------------------------
                  ootb     2.684k memsize (     0.000  retained)
                          30.000  objects (     0.000  retained)
                          10.000  strings (     0.000  retained)
      precompiled ootb     1.104k memsize (     0.000  retained)
                           9.000  objects (     0.000  retained)
                           1.000  strings (     0.000  retained)
  ```

  ```
  Calculating -------------------------------------
                 mixed     3.541k memsize (     0.000  retained)
                          46.000  objects (     0.000  retained)
                          20.000  strings (     0.000  retained)
     precompiled mixed     1.856k memsize (     0.000  retained)
                          29.000  objects (     0.000  retained)
                          13.000  strings (     0.000  retained)
  ```

This commit also adds `config.precompile_filter_parameters`, which
enables precompilation of `config.filter_parameters`.  It defaults to
`true` for `config.load_defaults 7.1` and above.