[MRC-139] Set MARS Price Source on Osmosis + Neutron Deployments

Summary
This proposal aims to add the MARS token as a price source on both Neutron and Osmosis outposts.

Motivation
To protect against slippage and malicious actors when distributing rewards, the Mars Protocol contracts ensure that the price does not deviate beyond a specified threshold. To determine the slippage, we use the Mars Oracle to price each asset.

As MARS token is not used as collateral anywhere on either outpost, it currently does not have a price source.

Risks
Because of the proposed implementation as a TWAP price, it is possible that the spot price could deviate significantly from the price reported by the (TWAP) oracle. During extreme volatility, this could result in short periods of time where the rewards distributor is unable to swap and distribute the protocol revenue.

Additionally, if the decimals used in proposed price source configuration do not match the decimals of the given asset, the protocol will report the incorrect price, by a significant margin.

Implementation
This proposal intends to apply changes to both Mars’ deployments on Osmosis and Neutron.

Neutron outpost

On the Neutron deployment, the oracle contract is controlled by the Mars DAO. If this proposal passes, the following message will be executed against the oracle contract:

{
	set_price_source: {
		denom: "factory/neutron1ndu2wvkrxtane8se2tr48gv7nsm46y5gcqjhux/MARS",
		price_source: {
		    astroport_twap: {
			pair_address: "neutron19jmaa83fjglqetsun8d6p57vpftqs2p0k843ey50ezkv4c3pntzqddezrq",
			tolerance: 120,
			window_size: 1800
		    }
	    }
	}
}

Osmosis Deployment
The oracle on this network is controlled by a multisig, so should this pass the changes would be executed by the builders multisig. For the osmosis deployment, this should be considered a signaling proposal

Copyright
Copyright and related rights waived via CC0.

Disclaimers/Disclosures
This proposal is being made by Mars Protocol Foundation, a Cayman Islands foundation company. Mars Protocol Foundation engages in research and development of the Mars Protocol. Mars Protocol Foundation and certain of its service providers and managers own MARS tokens and have financial interests related to this proposal. The aforementioned persons or their affiliates may also have financial interests in complementary or competing projects or ecosystems, entities or tokens, including NTRN. These statements are intended to disclose relevant facts and to help identify potential conflicts of interest, and should not be misconstrued as a complete description of all relevant interests or conflicts of interests; nor should they be construed as a recommendation to purchase or acquire any token or security.

This proposal is also subject to and qualified by the Mars Disclaimers/Disclosures. Mars Protocol Foundation may lack access to all relevant facts or may have failed to give appropriate weighting to available facts. Mars Protocol Foundation is not making any representation, warranty or guarantee regarding the accuracy or completeness of the statements herein, and Mars Protocol Foundation shall have no liability in the event of losses or damages ensuing from approval or rejection or other handling of the proposal. Each user and voter should undertake their own research and make their own independent interpretation and analysis of all relevant facts and issues to arrive at their own personal determinations of how to vote on the proposal.