[feature] #4059: snapshots "mode"

[0x009922]

Description

• Introduce mode of snapshots behaviour: read_write, readonly, and disabled
• Run SnapshotMaker actor only in read_write mode
• Configuration: remove snapshot.creation_enabled, add snapshot.mode
• Recursively create directories on snapshot writing ([suggestion] Snapshot configuration - ensure it creates a directory for itself #4296)
• Update related logging
• Add tests

Linked issue

Closes #4059, #4296

Benefits

More expected behaviour of snapshots for users?

[github-actions]

@BAStos525

[coveralls]

Pull Request Test Coverage Report for Build 8273909280

Details

• 129 of 170 (75.88%) changed or added relevant lines in 7 files are covered.
• 4072 unchanged lines in 79 files lost coverage.
• Overall coverage increased (+0.9%) to 57.677%

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Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
config/src/snapshot.rs	11	14	78.57%
core/src/kura.rs	2	6	33.33%
cli/src/lib.rs	0	12	0.0%
core/src/snapshot.rs	104	126	82.54%

Files with Coverage Reduction	New Missed Lines	%
primitives/src/conststr.rs	1	91.14%
ffi/derive/src/convert.rs	1	84.45%
primitives/src/lib.rs	1	0.0%
core/src/sumeragi/network_topology.rs	1	98.78%
crypto/src/signature/bls/mod.rs	2	0.0%
data_model/derive/src/has_origin.rs	3	95.16%
config/src/kura.rs	3	80.0%
primitives/src/addr.rs	3	63.82%
schema/derive/src/lib.rs	5	83.25%
config/src/logger.rs	5	72.73%

Totals
Change from base Build 7884695009:	0.9%
Covered Lines:	22603
Relevant Lines:	39189

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💛 - Coveralls