feat: implement bundler sponsorship

[dancoombs]

Proposed Changes

• Add a bundler sponsorship permission
• This permission enforces that the bundler pays all of the gas for the user operation, up to a max cost and in a time range
• Time range is best effort as its not enforced onchain.

TODO:

• Unit tests
• Local testing
• Docs

[codecov]

Codecov Report

Attention: Patch coverage is 25.78125% with 95 lines in your changes missing coverage. Please review.

Project coverage is 60.21%. Comparing base (9cddce7) to head (105044e).

Files with missing lines	Patch %	Lines
crates/builder/src/bundle_proposer.rs	18.91%	30 Missing ⚠️
crates/pool/src/server/remote/protos.rs	0.00%	22 Missing ⚠️
crates/pool/src/mempool/pool.rs	46.42%	15 Missing ⚠️
crates/rpc/src/types/permissions.rs	0.00%	9 Missing ⚠️
crates/pool/src/server/remote/server.rs	0.00%	6 Missing ⚠️
crates/types/src/gas.rs	0.00%	6 Missing ⚠️
crates/types/src/timestamp.rs	0.00%	6 Missing ⚠️
crates/sim/src/precheck.rs	92.85%	1 Missing ⚠️

Additional details and impacted files

Files with missing lines	Coverage Δ
crates/builder/src/emit.rs	28.08% <ø> (ø)
crates/rpc/src/eth/api.rs	92.79% <ø> (ø)
crates/types/src/user_operation/mod.rs	64.19% <ø> (ø)
crates/sim/src/precheck.rs	89.16% <92.85%> (+0.01%)	⬆️
crates/pool/src/server/remote/server.rs	0.00% <0.00%> (ø)
crates/types/src/gas.rs	60.00% <0.00%> (-40.00%)	⬇️
crates/types/src/timestamp.rs	94.61% <0.00%> (-3.53%)	⬇️
crates/rpc/src/types/permissions.rs	0.00% <0.00%> (ø)
crates/pool/src/mempool/pool.rs	96.00% <46.42%> (-1.12%)	⬇️
crates/pool/src/server/remote/protos.rs	1.93% <0.00%> (-0.09%)	⬇️
... and 1 more

Flag	Coverage Δ
unit-tests	60.21% <25.78%> (-0.16%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Components	Coverage Δ
rundler binary	0.00% <ø> (ø)
builder	67.98% <18.91%> (-0.32%)	⬇️
dev	∅ <ø> (∅)
pool	67.64% <23.21%> (-0.26%)	⬇️
provider	20.17% <ø> (ø)
rpc	26.25% <0.00%> (-0.13%)	⬇️
sim	81.34% <92.85%> (+0.01%)	⬆️
tasks	∅ <ø> (∅)
types	67.12% <0.00%> (-0.29%)	⬇️
utils	34.42% <ø> (ø)