feat: lending market improvements

[EvgeniiZaitsevCW]

Main changes

1. A new view function named programCounter() has been introduced to fetch the current lending program counter.
2. A bug in the auto repayment logic has been fixed.
3. A redundant check in the the auto repayment logic has been removed.
4. The outstanding balance math has been made more reliable and lightweight.
5. New checks when registering credit lines and liquidity pools have been added. The new checks prevent registration of an address that belongs to an inappropriate contract or not to a contract at all. This reduces the likelihood of misconfiguration of the lending market contract.
6. Unit tests for the lending market contract have been revised, optimized and improved.

Test Coverage

Test coverage details

File	% Stmts	% Branch	% Funcs	% Lines
contracts/	100.00	98.19	100.00	100.00
├─ LendingMarket.sol	100.00	98.17	100.00	100.00
├─ LendingMarketStorage.sol	100.00	100.00	100.00	100.00
├─ LendingMarketUUPS.sol	100.00	100.00	100.00	100.00
contracts/common/	100.00	100.00	100.00	100.00
├─ AccessControlExtUpgradeable.sol	100.00	100.00	100.00	100.00
contracts/common/interfaces/	100.00	100.00	100.00	100.00
├─ ICreditLineConfigurable.sol	100.00	100.00	100.00	100.00
├─ ILiquidityPoolAccountable.sol	100.00	100.00	100.00	100.00
contracts/common/interfaces/core/	100.00	100.00	100.00	100.00
├─ ICreditLine.sol	100.00	100.00	100.00	100.00
├─ ILendingMarket.sol	100.00	100.00	100.00	100.00
├─ ILiquidityPool.sol	100.00	100.00	100.00	100.00
contracts/common/libraries/	100.00	70.00	100.00	98.86
├─ ABDKMath64x64.sol	100.00	65.91	100.00	98.63
├─ Constants.sol	100.00	100.00	100.00	100.00
├─ Error.sol	100.00	100.00	100.00	100.00
├─ InterestMath.sol	100.00	100.00	100.00	100.00
├─ Loan.sol	100.00	100.00	100.00	100.00
├─ Round.sol	100.00	100.00	100.00	100.00
├─ SafeCast.sol	100.00	100.00	100.00	100.00
contracts/credit-lines/	100.00	97.37	100.00	100.00
├─ CreditLineConfigurable.sol	100.00	97.32	100.00	100.00
├─ CreditLineConfigurableUUPS.sol	100.00	100.00	100.00	100.00
contracts/liquidity-pools/	100.00	96.67	100.00	100.00
├─ LiquidityPoolAccountable.sol	100.00	96.55	100.00	100.00
├─ LiquidityPoolAccountableUUPS.sol	100.00	100.00	100.00	100.00
contracts/mocks/	100.00	100.00	100.00	100.00
├─ AccessControlExtUpgradeableMock.sol	100.00	100.00	100.00	100.00
├─ CreditLineMock.sol	100.00	100.00	100.00	100.00
├─ ERC20Mock.sol	100.00	100.00	100.00	100.00
├─ LendingMarketMock.sol	100.00	100.00	100.00	100.00
├─ LiquidityPoolMock.sol	100.00	100.00	100.00	100.00
contracts/testables/	100.00	100.00	100.00	100.00
├─ CreditLineConfigurableTestable.sol	100.00	100.00	100.00	100.00
-----------------------------------------	----------	----------	----------	----------
All files	94.33	94.31	100.00	99.85
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