[flake8] remove some unused imports.
library: added new function slices_of_runs()

Added slices_of_runs() which provides a generator that gives a list of
slices of runs of each unique value in the provided array. This should
only be used for arrays that have a few unique values or states.
Remove old min manoeuvring speed code.
Fix name of masked array test function.
Add derived multi-state parameter: 'Speed Control'
library: added new function first_available_parameter()
library: update function first_valid_parameter()

- Renamed from first_available_parameter().
- Added support for restricting validity check to phases.
Improve logging for GW At Liftoff/Touchdown.

- Added some review comments related to mask repair.
- Implemented additional unit tests.
Migrate some code to FlightDataProfiles.

Remove old vspeed_lookup code.
Add comment to Gross Weight Smoothed.
Minor tidying.
Strip out v-speed code to be replaced.
library: added new function lookup_table()
[flake8] minor tidying.
Added derived parameter V2.
Added derived parameter Vref.
Added derived parameter V2 Lookup.
Added derived parameter Vref Lookup.
Added derived parameter VMO Lookup.
Added derived parameter MMO Lookup.