feat: Build initial implementation with unit testing (SC-204)

[lucas-manuel]

NOTE: Interface is incomplete, will complete in a separate PR with natspec and overrides once everything is solidified.

Also left events and events testing out, but can add those as part of this PR if we want.

[linear]

SC-204 Build Spark GSM Bypass

This contract should allow the Maker chief contract to (un)pause any market on Spark mainnet. This should use the EMERGENCY_ADMIN role to silo the access out of an abundance of caution.

This type of contract is called a "Mom" contract in Maker-lingo. You can see an example of the structure here: https://github.com/makerdao/clipper-mom/blob/master/src/ClipperMom.sol

I would also like to consider making this forward-looking. If, for example, we could have another Spark Proxy deployed with EMERGENCY_ADMIN access which can only be triggered by this "Mom" to bypass the delay we could use this generalized structure instead of having to build a Mom contract for every specific function call on Spark.

[hexonaut]

I would use the exact structure of the ClipperMom including all naming. There is a single owner (pause proxy), the authority is the chief and the modifiers are onlyOwner (https://github.com/makerdao/clipper-mom/blob/master/src/ClipperMom.sol#L53) and auth (https://github.com/makerdao/clipper-mom/blob/master/src/ClipperMom.sol#L58) which calls the isAuthorized function which allows being called by the owner as well as the hat.

Keeping this consistent will reduce the cognitive overhead with emergency spells.

Also, add this to the bottom of the README:

***
*The IP in this repository was assigned to Mars SPC Limited in respect of the MarsOne SP*

I will continue review after these changes are made.

[lucas-manuel]

Getting full coverage in next PR

[hexonaut]

Some minor changes/fixes. Unit tests are also missing event tests.

[barrutko]

LGTM (HMU for approve after implementing Sam's comments)

[github-actions]

Coverage after merging sc-204-build-gsm-bypass into master will be

83.33%

Coverage Report

File	Stmts	Branches	Funcs	Lines	Uncovered Lines
src
SparkLendFreezerMom.sol	79.31%	50%	100%	83.33%	91–96

[hexonaut]

LGTM