[Fix] Coinselect: can_use_regular flagged as true even when target + fee < balance(regular)

[NeoZ666]

• Currently, can_use_regular only checks against target, not adding the estimated_fee.
• The coinselection crate also overshoots the fee by some sats, above the { estimated_fee + target } range.

Now,

• This gives an edge case where can_use_regular can be flagged as true, but coinselect fails due to the overshoot difference(This becomes an issue when the target amount is small). As a fix :
• Addition of fee during calc of can_use_x bool.
• Added a debug log for fee.
• Loops through swap if regular isn't enough. An important caveat : During manual selection, it instead throws a harderror when either chosen balance type is insufficient and does NOT loop through the other balance type.

Below is a swap with the new behavior :

[mojoX911]

Ack. Tested that the error is not occurring anymore.

[codecov]

Codecov Report

❌ Patch coverage is 90.96386% with 15 lines in your changes missing coverage. Please review.
✅ Project coverage is 78.25%. Comparing base (776b75d) to head (ab1f336).
⚠️ Report is 81 commits behind head on master.

Files with missing lines	Patch %	Lines
src/wallet/api.rs	90.96%	15 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #691      +/-   ##
==========================================
+ Coverage   68.87%   78.25%   +9.38%     
==========================================
  Files          35       49      +14     
  Lines        4932    15251   +10319     
==========================================
+ Hits         3397    11935    +8538     
- Misses       1535     3316    +1781     

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