(W)Gas token not in flashloan tokens can cause flashloan critical error for other flashloan tokens

[NIXBNT]

Bug Description

If the wrapped/gas token is not in the flashloan tokens the db Token object in the TradeInstruction object does not populate for it leading to this error:
fastlane-bot\fastlane_bot\helpers\tradeinstruction.py", line 145, in __post_init__ self._tknout_address = TokenOut.address ^^^^^^^^^^^^^^^^ AttributeError: 'NoneType' object has no attribute 'address'

The reason is because when these Token objects are created in interface.py/populate_tokens() the flashloan token list is the gate-keeper:

Severity (High/Medium/Low)

Moderate - Likely to affect FLT/(W)Gas token pairs disproportionately but also critically

Steps to Reproduce

Requires an open arb to trigger the building of TradeInstruction objects
python main.py --blockchain=sei --backdate_pools=False --arb_mode=multi_pairwise_all --exchanges=carbon_v1 --randomizer=3 --flashloan_tokens=0x9e7A8e558Ce582511f4104465a886b7bEfBC146b --target_tokens=0x9e7A8e558Ce582511f4104465a886b7bEfBC146b,0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE,0x57eE725BEeB991c70c53f9642f36755EC6eb2139 --alchemy_max_block_fetch=100 --default_min_profit_gas_token=0.000001 --read_only=False --self_fund=False

Expected Behavior

Arbs using non-gas flts possible

Actual Behavior

Arbs using non-gas flts not possible

Impact Analysis (to be filled by contributors)

• Automated Tests: Are there existing tests covering this? Do we need new tests?
• Risks: Potential areas affected by this bug and its probable fix
• Performance: Is this bug affecting performance?
• Monitoring: Does this affect any current monitoring? Any new alerts needed?
• Logging: Any changes required in logging?
• Documentation: Updates needed in documentation?