Add signature parameter to estimate_fee

[cptartur]

Please check if the PR fulfills these requirements

• The formatter, linter, and tests all run without an error
• Tests for the changes have been added (for bug fixes/features)
• Docs have been added / updated (for bug fixes / features)

What kind of change does this PR introduce? (Bug fix, feature, docs update, ...)

Adds signature parameter to Contract.estimate_fee method

• What is the current behavior? (You can also link to an open issue here)

Signature is not added

What is the new behavior (if this is a feature change)?

Signature is added to invoke function

Does this PR introduce a breaking change? (What changes might users need to make in their application due to this PR?)

No

Other information

n/a

[codecov]

Codecov Report

Merging #217 (f40608a) into development (c3804bb) will not change coverage.
The diff coverage is 100.00%.

@@             Coverage Diff              @@
##           development     #217   +/-   ##
============================================
  Coverage        97.84%   97.84%           
============================================
  Files               29       29           
  Lines              976      976           
============================================
  Hits               955      955           
  Misses              21       21           

Impacted Files	Coverage Δ
starknet_py/contract.py	99.54% <100.00%> (ø)

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