Add Filter ext algebraic flag

[rodrigomha]

This PR also adds the temporary fix to allow dVOC and Droop models to be included in the ReferenceBus.

[github-actions[bot]]

Performance Results	Version	Precompile Time
Master	13.309709247
This Branch	13.427160653

Version	Execute Time
Master-Build ResidualModel	15.570660221
Master-Execute ResidualModel	75.279249866
Master-Build MassMatrixModel	1.81327306
Master-Execute MassMatrixModel	77.929229247
This Branch-Build ResidualModel	15.869284924
This Branch-Execute ResidualModel	72.48028043
This Branch-Build MassMatrixModel	1.766536397
This Branch-Execute MassMatrixModel	77.22958341

ResidualModel and MassMatrixModel performance results should be compared between versions and not between models due to the execution order of the tests

[codecov[bot]]

Codecov Report

Merging #291 (78d8338) into master (73a5da5) will increase coverage by 0.67%. The diff coverage is 100.00%.

Additional details and impacted files

[](https://codecov.io/gh/NREL-SIIP/PowerSimulationsDynamics.jl/pull/291?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=NREL-SIIP) ```diff @@ Coverage Diff @@ ## master #291 +/- ## ========================================== + Coverage 90.13% 90.80% +0.67% ========================================== Files 63 63 Lines 7357 7309 -48 ========================================== + Hits 6631 6637 +6 + Misses 726 672 -54 ``` | Flag | Coverage Δ | | |---|---|---| | unittests | `90.80% <100.00%> (+0.67%)` | :arrow_up: | Flags with carried forward coverage won't be shown. [Click here](https://docs.codecov.io/docs/carryforward-flags?utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=NREL-SIIP#carryforward-flags-in-the-pull-request-comment) to find out more. | [Impacted Files](https://codecov.io/gh/NREL-SIIP/PowerSimulationsDynamics.jl/pull/291?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=NREL-SIIP) | Coverage Δ | | |---|---|---| | [src/models/inverter\_models/filter\_models.jl](https://codecov.io/gh/NREL-SIIP/PowerSimulationsDynamics.jl/pull/291/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=NREL-SIIP#diff-c3JjL21vZGVscy9pbnZlcnRlcl9tb2RlbHMvZmlsdGVyX21vZGVscy5qbA==) | `96.20% <100.00%> (+0.09%)` | :arrow_up: | | [src/models/inverter\_models/outer\_control\_models.jl](https://codecov.io/gh/NREL-SIIP/PowerSimulationsDynamics.jl/pull/291/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=NREL-SIIP#diff-c3JjL21vZGVscy9pbnZlcnRlcl9tb2RlbHMvb3V0ZXJfY29udHJvbF9tb2RlbHMuamw=) | `99.44% <100.00%> (+<0.01%)` | :arrow_up: | | [src/base/simulation.jl](https://codecov.io/gh/NREL-SIIP/PowerSimulationsDynamics.jl/pull/291/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=NREL-SIIP#diff-c3JjL2Jhc2Uvc2ltdWxhdGlvbi5qbA==) | `87.80% <0.00%> (+0.84%)` | :arrow_up: | | [src/base/perturbations.jl](https://codecov.io/gh/NREL-SIIP/PowerSimulationsDynamics.jl/pull/291/diff?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=NREL-SIIP#diff-c3JjL2Jhc2UvcGVydHVyYmF0aW9ucy5qbA==) | `58.57% <0.00%> (+9.17%)` | :arrow_up: |